territorial (adj.) Look up territorial at Dictionary.com
1620s, "of or pertaining to a territory," from Late Latin territorialis, from territorium (see territory). In reference to British regiments, from 1881. In reference to an area defended by an animal, from 1920. Territorial waters is from 1841. Territorial army "British home defense" is from 1908. Territorial imperative "animal need to claim and defend territory" is from 1966.
territoriality (n.) Look up territoriality at Dictionary.com
"possession and control of territory," 1839, as a concept in international law, from territorial + -ity. From 1941 in reference to animal behavior.
territory (n.) Look up territory at Dictionary.com
late 14c., "land under the jurisdiction of a town, state, etc.," probably from Latin territorium "land around a town, domain, district," from terra "earth, land" (see terrain) + -orium, suffix denoting place (see -ory). Sense of "any tract of land, district, region" is first attested c. 1600. Specific U.S. sense of "organized self-governing region not yet a state" is from 1799. Of regions defended by animals from 1774.

"Since -torium is a productive suffix only after verbal stems, the rise of terri-torium is unexplained" [Michiel de Vaan, "Etymological Dictionary of Latin and the other Italic Languages"]. An alternative theory, somewhat supported by the vowels of the original Latin word, suggests derivation from terrere "to frighten" (see terrible); thus territorium would mean "a place from which people are warned off."
terror (n.) Look up terror at Dictionary.com
early 15c., "something that intimidates, an object of fear," from Old French terreur (14c.), from Latin terrorem (nominative terror) "great fear, dread, alarm, panic; object of fear, cause of alarm; terrible news," from terrere "fill with fear, frighten," from PIE root *tres- "to tremble" (see terrible).

From c. 1500 as "fear so great as to overwhelm the mind." Meaning "quality of causing dread" is attested from 1520s. Sense of "a person fancied as a source of terror" (often with deliberate exaggeration, as of a naughty child) is recorded from 1883. Terror bombing first recorded 1941, with reference to German air attack on Rotterdam. Terror-stricken is from 1831. The Reign of Terror in French history (March 1793-July 1794) was the period when the nation was ruled by a faction whose leaders made policy of killing by execution anyone deemed an impediment to their measures; so called in English from 1801. Old English words for "terror" included broga and egesa.
terrorise (v.) Look up terrorise at Dictionary.com
chiefly British English spelling of terrorize (q.v.); for suffix, see -ize. Related: Terrorised; terrorising.
terrorism (n.) Look up terrorism at Dictionary.com
1795, in specific sense of "government intimidation during the Reign of Terror in France" (March 1793-July 1794), from French terrorisme, from Latin terror (see terror).
If the basis of a popular government in peacetime is virtue, its basis in a time of revolution is virtue and terror -- virtue, without which terror would be barbaric; and terror, without which virtue would be impotent. [Robespierre, speech in French National Convention, 1794]
General sense of "systematic use of terror as a policy" is first recorded in English 1798 (in reference to the Irish Rebellion of that year). At one time, a word for a certain kind of mass-destruction terrorism was dynamitism (1883); and during World War I frightfulness (translating German Schrecklichkeit) was used in Britain for "deliberate policy of terrorizing enemy non-combatants."
terrorist (n.) Look up terrorist at Dictionary.com
in the modern sense, 1944, especially in reference to Jewish tactics against the British in Palestine -- earlier it was used of extremist revolutionaries in Russia who attempted to demoralize the government by terror (1866); and Jacobins during the French Revolution (1795) -- from French terroriste; see terror + -ist (also see terrorism).
The term now usually refers to a member of a clandestine or expatriate organization aiming to coerce an established government by acts of violence against it or its subjects. [OED]
The tendency of one party's terrorist to be another's guerilla or freedom fighter was noted in reference to the British action in Cyprus (1956) and the war in Rhodesia (1973). The word terrorist has been applied, at least retroactively, to the Maquis resistance in occupied France in World War II (as in in the "Spectator," Oct. 20, 1979).
terroristic (adj.) Look up terroristic at Dictionary.com
1842, from terrorist + -ic. Related: Terroristical.
terrorize (v.) Look up terrorize at Dictionary.com
"coerce or deter by terror," 1823, from terror + -ize (also see terrorism). Related: Terrorized; terrorizing; terrorization.
terry (n.) Look up terry at Dictionary.com
"loop raised in pile-weaving, left uncut," 1784, of uncertain origin, possibly an alteration of French tiré "drawn," from past participle of tirer "draw out" (compare German gezogener Sammet "drawn velvet").
terse (adj.) Look up terse at Dictionary.com
1590s (implied in tersely), "clean-cut, burnished, neat," from French ters "clean," and directly from Latin tersus "wiped off, clean, neat," from past participle of tergere "to rub, polish, wipe." Sense of "concise or pithy in style or language" is from 1777, which led to a general sense of "neatly concise." The pejorative meaning "brusque" is a fairly recent development. Related: Terseness.
tertiary (adj.) Look up tertiary at Dictionary.com
1650s, "of the third order, rank, degree, etc.," from Latin tertiarius "of or pertaining to a third," from tertius "third, a third," from root of tres "three" (see three). The geological sense (with capital T-) of "era after the Mesozoic" (which formerly was called the Secondary) is attested from 1794, after Italian terziari, used in this sense 1760 by Italian geologist Giovanni Arduino (1714-1795).
tertium quid (n.) Look up tertium quid at Dictionary.com
something indeterminate between two other things, 1724, Latin, literally "third something," from tertius "third, a third," from the root of tres "three" (see three). A loan-translation of Greek triton ti (Plato), used in alchemy for "unidentified element present in a combination of two known ones." The Latin word also figures in phrases tertium non datur "no third possibility exists," and tertius gaudens "a third party that benefits from conflict between the other two."
terza rima (n.) Look up terza rima at Dictionary.com
1819, Italian, literally "third rhyme." Dante's measure: a-b-a-b-c-b-c-d-c-, etc.
tesla (n.) Look up tesla at Dictionary.com
"unit of magnetic flux density," 1960, from Nikola Tesla (1856-1943), Croatian-born U.S. engineer. Tesla coil is attested from 1896.
tessellated (adj.) Look up tessellated at Dictionary.com
1690s, from Late Latin tessellatus "made of small square stones or tiles," past participle of tesselare, from tessella "small square stone or tile," diminutive of tessera "a cube or square of stone or wood," perhaps from Greek tessera, neuter of tesseres, Ionic variant of tessares "four" (see four), in reference to four corners. Related: Tessellate (v.), a 1791 back-formation (from 1826 as an adjective, 1909 as a noun); tessellating.
tessellation (n.) Look up tessellation at Dictionary.com
"minute arrangement of parts or colors," 1650s, noun of action from Late Latin tessellatus (see tessellated).
tessera (n.) Look up tessera at Dictionary.com
plural tesserae, "small, square piece of stone," 1650s, from Latin tessera "a die, cube, square tablet with writing on it" used as a token or ticket, from Ionic Greek tessera, neuter of tesseres (Attic tessares) "four" (see four).
tesseract (n.) Look up tesseract at Dictionary.com
"four-dimensional 'cube,'" 1888, from tessera + Greek aktis "ray" (see actino-).
test (n.) Look up test at Dictionary.com
late 14c., "small vessel used in assaying precious metals," from Old French test, from Latin testum "earthen pot," related to testa "piece of burned clay, earthen pot, shell" (see tete).

Sense of "trial or examination to determine the correctness of something" is recorded from 1590s. The connecting notion is "ascertaining the quality of a metal by melting it in a pot." Test Act was the name given to various laws in English history meant to exclude Catholics and Nonconformists from office, especially that of 1673, repealed 1828. Test drive (v.) is first recorded 1954.
test (v.) Look up test at Dictionary.com
1748, "to examine the correctness of," from test (n.), on the notion of "put to the proof." Earlier "assay gold or silver" in a test (c. 1600). Meaning "to administer a test" is from 1939; sense of "undergo a test" is from 1934. Related: Tested; testing.
test-tube (n.) Look up test-tube at Dictionary.com
1809, from test (n.) + tube (n.). So called because it originally was used to test the properties of liquids. Test-tube baby is recorded from 1935.
testament (n.) Look up testament at Dictionary.com
late 13c., "last will disposing of property," from Latin testamentum "a last will, publication of a will," from testari "make a will, be witness to," from testis "witness," from PIE *tri-st-i- "third person standing by," from root *tris- "three" (see three) on the notion of "third person, disinterested witness."

Use in reference to the two divisions of the Bible (early 14c.) is from Late Latin vetus testamentum and novum testamentum, loan-translations of Greek palaia diatheke and kaine diatheke. Late Latin testamentum in this case was a confusion of the two meanings of Greek diatheke, which meant both "covenant, dispensation" and "will, testament," and was used in the former sense in the account of the Last Supper (see testimony) but subsequently was interpreted as Christ's "last will."
testamentary (adj.) Look up testamentary at Dictionary.com
"pertaining to a will or wills," mid-15c., from Latin testamentarius, from testamentum (see testament).
testate (adj.) Look up testate at Dictionary.com
"having left a valid will," late 15c., from Latin testatus "public, manifest, published," past participle of testari "make a will, be witness to, declare" (see testament).
testator (n.) Look up testator at Dictionary.com
c. 1400, from Anglo-French testatour (c. 1300), from Late Latin testator "one who makes a will," from testari (see testate). Fem. form testatrix is attested from 1590s.
tester (n.1) Look up tester at Dictionary.com
"one who tests, puts to trial, or assays," 1660s, agent noun from test (v.). Earlier "a crucible" for trying metals by heating them (mid-15c.).
tester (n.2) Look up tester at Dictionary.com
"canopy over a four-post bed," mid-14c., from Medieval Latin testerium, from testera "head-stall" of the bridle of a horse, extended use and form of Late Latin testa "skull," in Vulgar Latin "head" (see tete). From Medieval Latin testa as "head" also come tester in obsolete senses of "piece of armor for the head" (late 14c., via Old French testiere) and "coin of Henry VIII" (1546), the first English coin to bear a true portrait.
testes (n.) Look up testes at Dictionary.com
see testis.
testicle (n.) Look up testicle at Dictionary.com
early 15c., alteration of testicule (late 14c.), from Latin testiculus, diminutive of testis "testicle" (see testis). Old English had beallucas (see ballocks) and herþan, probably originally "leather bag" (compare heorþa "deer-skin"). The commonest slang terms for them in other languages are words that mean "balls," "stones," "nuts," "eggs."
testicular (adj.) Look up testicular at Dictionary.com
1650s, from Latin testiculus (see testicle) + -ar.
testify (v.) Look up testify at Dictionary.com
late 14c., "give legal testimony, affirm the truth of, bear witness to;" of things, c. 1400, "serve as evidence of," from Anglo-French testifier, from Latin testificari "bear witness, show, demonstrate," also "call to witness," from testis "a witness" (see testament) + root of facere "to make" (see factitious). Biblical sense of "openly profess one's faith and devotion" is attested from 1520s. Related: Testified; testifying; testification.
testimonial (adj.) Look up testimonial at Dictionary.com
early 15c., "of or pertaining to testimony," in part from testimonial (n.) and from Late Latin testimonialis, from Latin testimonium (see testimony). Originally especially in phrase letters testimonial (Middle French lettres testimoniaulx, Latin litteræ testimoniales) "document or documents attesting to a fact or to the good standing of the bearer," literally "letters serving for evidence."
testimonial (n.) Look up testimonial at Dictionary.com
"statement, declaration," also "writing testifying to one's qualification or character," early 15c. (from Old French testimonial, variant of tesmoignal), short for letters testimonial (see testimonial (adj.)). Meaning "gift presented as an expression of appreciation" is from 1838.
testimony (n.) Look up testimony at Dictionary.com
c. 1400, "proof or demonstration of some fact, evidence, piece of evidence;" early 15c., "legal testimony, sworn statement of a witness," from Old North French testimonie (Old French testimoine 11c.), from Latin testimonium "evidence, proof, witness, attestation," from testis "a witness, one who attests" (see testament) + -monium, suffix signifying action, state, condition. Despite the common modern assertion, the sense of the word is unlikely to have anything to do with testicles (see testis).

Earliest attested sense in English is "the Ten Commandments" (late 14c.), from Vulgate use of Late Latin testimonium, along with Greek to martyrion (Septuagint), translations of Hebrew 'eduth "attestation, testimony" (of the Decalogue), from 'ed "witness."
testis (n.) Look up testis at Dictionary.com
(plural testes), 1704, from Latin testis "testicle," usually regarded as a special application of testis "witness" (see testament), presumably because it "bears witness to male virility" [Barnhart]. Stories that trace the use of the Latin word to some supposed swearing-in ceremony are modern and groundless.

Compare Greek parastatai "testicles," from parastates "one that stands by;" and French slang témoins, literally "witnesses." But Buck thinks Greek parastatai "testicles" has been wrongly associated with the legal sense of parastates "supporter, defender" and suggests instead parastatai in the sense of twin "supporting pillars, props of a mast," etc. Or it might be a euphemistic use of the word in the sense "comrades." OED, meanwhile, points to Walde's suggestion of a connection between testis and testa "pot, shell, etc." (see tete).
testosterone (n.) Look up testosterone at Dictionary.com
male sex hormone, 1935, from German Testosteron (1935), coined from a presumed comb. form of Latin testis "testicle" (see testis) + first syllable of sterol + chemical ending -one.
testy (adj.) Look up testy at Dictionary.com
early 15c., "impetuous, rash," altered from Middle English testif "headstrong" (late 14c.), from Anglo-French testif, Old French testu (Modern French têtu) "stubborn, headstrong, obstinate," literally "heady," from teste "head" (see tete). Meaning "easily irritated, irascible" is first recorded 1520s. Related: Testily; testiness.
Tet (n.) Look up Tet at Dictionary.com
Vietnamese lunar new year, 1885, short for Tet Nguyen Dan "feast of the first day." The North Vietnamese Tet Offensive in the U.S. Vietnam War began Jan. 30, 1968.
tetanus (n.) Look up tetanus at Dictionary.com
infectious disease, late 14c., from Latin tetanus "tetanus," from Greek tetanos "tetanus, muscular spasm," literally "a stretching, tension," from teinein "to stretch" (see tenet); "so called because the disease is characterized by violent spasms and stiffness of the muscles" [Barnhart]. Related: Tetanoid (adj.).
tetany (n.) Look up tetany at Dictionary.com
1890, from French tétanie "intermitent tetanus," from Modern Latin tetania (see tetanus).
tetched (adj.) Look up tetched at Dictionary.com
1930, U.S. colloquial variant of touched in the sense of "slightly crazy" (see touch (v.)).
tetchy (adj.) Look up tetchy at Dictionary.com
"easily irritated," 1592, teachie, in "Romeo & Juliet" I.iii.32; of uncertain origin. Perhaps from Middle English tatch "a mark, quality," derived via Old French from Vulgar Latin *tecca, from a Germanic source akin to Old English tacen (see token).
tete (n.) Look up tete at Dictionary.com
as a type of women's tall dressed hair or wig, 1756, from French tête "head," Old French teste, from Latin testa, literally "piece of earthenware, tile, potsherd; earthen pot, pitcher, jug; shell of shellfish," related to Latin testudo "tortoise" and texere "to weave" (compare Lithuanian tištas "vessel made of willow twigs;" see texture (n.)).

The "head" sense arose in Vulgar Latin, perhaps as a humorous use of the "jug, pot" meaning, or via Late Latin use of testa as "skull," from testa (capitis) "shell (of the head)." Compare German Kopf "head" from the root of English cup (n.).
tete-a-tete (n.) Look up tete-a-tete at Dictionary.com
"a private meeting," from French tête-à-tête, literally "head-to-head," from Old French teste "head" (see tete). The adjective, "private, confidential, with none present but the persons concerned" is recorded from 1728; as an adverb from 1790.
tether (n.) Look up tether at Dictionary.com
late 14c., "rope for fastening an animal," not found in Old English, probably from a Scandinavian source akin to Old Norse tjoðr "tether," from Proto-Germanic *teudran (cognates: Danish tøir, Old Swedish tiuther, Swedish tjuder, Old Frisian tiader, Middle Dutch tuder, Dutch tuier "line, rope," Old High German zeotar "pole of a cart"), from PIE root *deu- "to fasten" + instrumentive suffix *-tro-. Figurative sense of "measure of one's limitations" is attested from 1570s.
tether (v.) Look up tether at Dictionary.com
late 14c. (implied in tethering), "confine by a tether," originally of grazing animals, from tether (n.). Figurative use also from late 14c. Related: Tethered.
tetherball (n.) Look up tetherball at Dictionary.com
also tether-ball, 1900, from tether (n.) + ball (n.1).
Tethys Look up Tethys at Dictionary.com
name for the sea that anciently lay between Eurasia and Africa-Arabia, coined 1893 by German geologist Eduard Suess (1831-1914), from Tethys, name of a Greek sea goddess, sister and consort of Oceanus.
Teton (n.) Look up Teton at Dictionary.com
member of a western Sioux people, 1806, from Dakota titonwan, literally "dwellers on the prairie," from thi + huwa. Not related to the Grand Teton mountain range.