Online Etymology Dictionary

Tong: "Chinese secret society," 1883, from Cantonese t'ong "assembly hall."
tongs (n.): Old English tange, tang "tongs," from Proto-Germanic *tango (cf. Old Saxon tanga, Old Norse töng, Swedish tång, Old Frisian tange, Middle Dutch tanghe, Dutch tang, Old High German zanga, German Zange), literally "that which bites," from PIE root *dank- "bite" (cf. Sanskrit dasati "biter;" Greek daknein "to bite," dax "biting"). For sense evolution, cf. French mordache "tongs," from mordre "to bite."
tongue (n.): Old English tunge "organ of speech, speech, language," from Proto-Germanic *tungon (cf. Old Saxon and Old Norse tunga, Old Frisian tunge, Middle Dutch tonghe, Dutch tong, Old High German zunga, German Zunge, Gothic tuggo), from PIE *dnghwa- (cf. Latin lingua "tongue, speech, language," from Old Latin dingua; Old Irish tenge, Welsh tafod, Lithuanian liezuvis, Old Church Slavonic jezyku).

For substitution of -o- for -u-, see come. The spelling of the ending of the word apparently is a 14c. attempt to indicate proper pronunciation, but the result is "neither etymological nor phonetic, and is only in a very small degree historical" [OED]. Meaning "foreign language" is from 1530s. Tongue-tied is first recorded 1520s.
tongue (v.): "to touch with the tongue, lick," 1680s, from tongue (n.). Earlier as a verb it meant "drive out by order or reproach" (late 14c.). Related: Tongued; tonguing.
tongue-in-cheek (adj.): 1933, from phrase to speak with one's tongue in one's cheek "to speak insincerely" (1748), which somehow must have been suggestive of sly irony or humorous insincerity, but the exact notion is obscure.
tongued (adj.): "speaking in a certain manner," late 14c., in compounds and combinations, from tongue (n.).
tongueless (adj.): late 14c., "having no tongue;" early 15c. as "speechless, silent," from tongue (n.) + -less.
tonic (n.1): "a tonic medicine," 1799, from tonic (adj.).
tonic (adj.): 1640s, "relating to or characterized by muscular tension," from Greek tonikos "of stretching," from tonos "a stretching" (see tenet). The meaning "maintaining the healthy firmness of tissues" is recorded from 1680s, first extended 1756 to "having the property of restoring to health."
tonic (n.2): in the musical sense, 1760, from tone (n.) + -ic. Related: Tonicity.
tonify (v.): 1786, from tone + -ify. Related: Tonified; tonifying.
tonight: Old English toniht "tomorrow night" (Anglo-Saxon day began at sunset), from to "at, on" (see to) + niht (see night). Written as two words until 18c., after which it was to-night until early 20c.
tonite: colloquial shortening of tonight, attested by 1918.
Present-day student notices on bulletin boards, etc., read oftener than not, "Party Friday Nite," "Meeting Tonite," "Kum Tonite," etc. [Louise Pound, Spelling-Manipulation and Present-Day Advertising, "Dialect Notes," 1923]
tonnage (n.): early 15c., from ton + -age. Originally was "tax or duty on wine imported in tuns."
tonne (n.): 1877, French form of ton, adopted for English use to denote a metric ton (1,000 kg.).
tonneau (n.): 1901 as a part of an automobile, from French tonneau, literally "cask, tun." (see tun).
tonsil (n.): c.1600, from Latin tonsillae (plural) "tonsils," diminutive of toles "goiter," which is perhaps of Gaulish origin.
tonsillectomy (n.): 1899, from tonsil + -ectomy. A hybrid with a Greek ending. A correct formation all from Greek would be amygdalectomy.
tonsillitis (n.): also tonsilitis, 1801, from tonsil + -itis.
tonsillolith (n.): 1903, from tonsillo-, comb. form of tonsil + -lith "stone."
tonsorial (adj.): "pertaining to barbers," 1813, from Latin tonsorius "of or pertaining to shearing or shaving," from tonsor "a shaver or barber," from tonsus, past participle of tondere "to shear, shave" (see tonsure). Tonsorious in the same sense is attested from 1650s.
tonsure (n.): late 14c., "shaving of the head or part of it as a religious rite," from Anglo-French tonsure (mid-14c.), from Old French tonsure (14c.), from Latin tonsura "a shearing, clipping," from tonsus, past participle of tondere "to shear, shave," from PIE *tend-, from root *tem- "to cut" (see tome). The verb is attested from 1793. Related: Tonsured; tonsuring.
tontine: 1765, from French tontine, named for Lorenzo Tonti, Neapolitan banker who in 1653 first proposed this method of raising money.
Tonto: former term for the Western Apaches, from Spanish, literally "foolish;" probably a translation of a name given to the people by other branches of the Apache, e.g. Chiricahua Apache /bini:'édiné/, Mescalero Apache /bini:'édinendé/, both literally "people without minds," and used to designate the Western Apaches. Spanish tonto is said to be originally a nursery word, used for its sound.
tony (adj.): 1877, American English slang, from high-toned. It was the name of a reddish-brown fashion color in the 1920s.
Tony: 1947, awards given by American Theatre Wing (New York), from nickname of U.S. actress, manager, and producer Antoinette Perry (1888-1946).
Tony Curtis: style of men's haircut (usually with a DA at the back), 1956, from screen name of U.S. film star Bernard Schwarz (b.1925).
too (adv.): "in addition, in excess," late Old English, stressed variant of Old English prep. to "in the direction of, furthermore" (see to). The spelling with -oo is first recorded 1590. Use after a verb, for emphasis (e.g. did, too!) is attested from 1914. German zu unites the senses of English to and too. Slang too-too "excessive in social elegance" first recorded 1881. Too much "excellent" first recorded 1937 in jazz slang.
toodle-oo: colloquial "good-bye" word, 1907, of unknown origin; variant tooraloo is recorded from c.1921.
took: past tense of take, from late Old English toc, past tense of tacan (see take).
tool (n.): Old English tol "instrument, implement," from Proto-Germanic *tolan (cf. Old Norse tol), from a verb stem represented by Old English tawian "prepare." The ending is the instrumental suffix -l (e.g. shovel). Figurative sense of "person used by another for his own ends" is recorded from 1660s. Slang meaning "penis" first recorded 1550s.
tool (v.): "to drive a vehicle," 1812, probably from tool (n.). The meaning "to work or shape with a tool" is recorded from 1815; that of "equip (a factory) with machine tools" is from 1927. Related: Tooled; tooling.
toolbar (n.): 1960 as a frame fitted to a tractor to hold tools; from tool (n.) + bar (n.1). Computer sense is attested from 1991.
Among 100-odd new features in Excel 3.0 is a row of "buttons" on the screen called the Toolbar. Located under the pull-down menus, the Toolbar provides rapid access to frequently used commands. ["Popular Science," April 1991.]
toolbox (n.): also tool-box, 1832, from tool (n.) + box (n.1).
toolkit (n.): 1963, from tool (n.) + kit (1).
toon (n.): colloquial shortening of cartoon, attested by 1985.
toot (v.): c.1500, ultimately imitative, also found in Middle Low German and Low German tuten "blow a horn." Related: Tooted; tooting. The noun is recorded from 1640s. Meaning "cocaine" is attested by 1977. Tooting as a strong affirmative (e.g. you're damned tootin') is attested from 1932, American English. Toots as a slang familiar form of address to a woman or girl is recorded from 1936, American English.
toot sweet: "right away, promptly," 1917, American English, representing U.S. soldiers' mangled adaptation of French tout de suite.
tooth (n.): Old English toð (plural teð), from Proto-Germanic *tanth, *tunth (cf. Old Saxon, Danish, Swedish, Dutch tand, Old Norse tönn, Old Frisian toth, Old High German zand, German Zahn, Gothic tunþus), from PIE *dont-/*dent- "tooth" (cf. Sanskrit danta, Greek odontos, Latin dens, Lithuanian dantis, Old Irish det, Welsh dent). Plural form teeth is an instance of i-mutation. Application to tooth-like parts of other objects (saws, combs, etc.) first recorded 1520s.
toothache (n.): late 14c., from tooth + ache (n.).
toothbrush (n.): 1650s, from tooth + brush (n.1).
toothless (adj.): late 14c., in literal sense, from tooth + -less. Figurative sense of "dull" is recorded from 1590s; that of "lacking enforcement powers" is first recorded 1961. Related: Toothlessly; toothlessness.
toothpaste (n.): 1832, from tooth + paste (n.).
toothpick (n.): late 15c., from tooth + pick (n.).
toothsome (adj.): "pleasant to the taste," 1560s; the figurative sense of "attractive" (1550s) is a bit older; from tooth + -some.
tootle (v.): 1820, frequentative of toot.
tootsy (n.): also tootsie, 1854, baby-talk substitution for foot. Candy bar Tootsie Roll patent claims use from 1908.
top (n.1): "highest point," Old English top "summit, crest, tuft," from Proto-Germanic *tuppaz (cf. Old Norse toppr "tuft of hair," Old Frisian top "tuft," Old Dutch topp, Dutch top, Old High German zopf "end, tip, tuft of hair," German Zopf "tuft of hair"); no certain connections outside Germanic except a few Romanic words probably borrowed from Germanic.

Few Indo-European languages have a word so generic, which can be used of the upper part or surface of just about anything. More typical is German, which has Spitze for sharp peaks (mountains), oberfläche for the upper surface of flat things (such as a table). Top dog first attested 1900; top-drawer (1920) is from British expression out of the top drawer "upper-class."
top (n.2): "toy that spins on a point," late Old English top, probably a special use of top (n.1), but the modern word is perhaps via Old French topet, which is from a Germanic source akin to the root of English top (n.1). As a type of seashell, first recorded 1680s.
top (v.): "put a top on," 1580s, from top (n.1). The meaning "be higher or greater than" also is first recorded 1580s. Related: Topped; topping. To top off "finish" is colloquial from 1836;