Online Etymology Dictionary

throng (n.): c.1300, probably shortened from Old English geþrang "crowd, tumult" (related to verb þringan "to push, crowd, press"), from Proto-Germanic *thrangan (cf. Old Norse þröng, Dutch drang, German Drang "crowd, throng").
throng (v.): "go in a crowd," 1530s, from throng (n.). Related: Thronged; thronging.
throstle (n.): "thrush," Old English þrostle, from Proto-Germanic *thrustalo (cf. Old Saxon throsla, Old High German droscala, German Drossel "thrush"), altered from (perhaps a diminutive of) *thurstaz (see thrush (n.1)), though OED considers this a distinct word from the same PIE root.
throttle (v.): "strangle to death," c.1400, probably from Middle English throte "throat" (see throat). Related: Throttled; throttling. The noun, in the mechanical sense, is first recorded 1870s, from throttle-valve (1824), but was used earlier as a synonym for "throat" (1540s); it appears to be an independent formation, not derived from the verb.
through (prep.): c.1300, metathesis of Old English þurh, from West Germanic *thurkh (cf. Old Saxon thuru, Old Frisian thruch, Middle Dutch dore, Dutch door, Old High German thuruh, German durch, Gothic þairh "through"), from PIE root *tere- "to cross over, pass through, overcome" (cf. Sanskrit tirah, Avestan taro "through, beyond," Latin trans "beyond," Old Irish tre, Welsh tra "through").

Not clearly differentiated from thorough until early Modern English. Spelling thro was common 15c.-18c. Reformed spelling thru (1917) is mainly American English.
throughly (adv.): "fully, completely," mid-15c., from through + -ly (2). Archaic alternative to thoroughly.
throughout (prep.): late Old English þurhut; see through + out (adv.), and cf. German durchaus, 16c.
throughput (n.): "energy, activity," 1808, Scottish slang; from through + put. Industrial sense is from 1915.
throughway (n.): "expressway, large toll road," 1934, American English, from through + way.
throw (v.): "to project, propel," c.1300, from Old English þrawan "to twist, turn writhe" (past tense þreow, past participle þrawen), from Proto-Germanic *thræ- (cf. Old Saxon thraian, Middle Dutch dræyen, Dutch draaien, Old High German draen, German drehen "to turn, twist;" not found in Scandinavian or Gothic), from PIE *tere- "to rub, turn, rub by turning, bore" (cf. Sanskrit turah "wounded, hurt," Greek teirein "to rub, rub away," Latin terere "to rub, thresh, grind, wear away," Old Church Slavonic tiro "to rub," Lithuanian trinu "to rub," Old Irish tarathar "borer," Welsh taraw "to strike").

Not the usual Old English word for "to throw" (weorpan, related to warp (v.) was common in this sense). The sense evolution may be via the notion of whirling a missile before throwing it. The sense of "put by force" (e.g. throw in jail) is first recorded 1560; that of "to confuse, flabbergast" is from 1844; that of "lose deliberately" is from 1868.

To throw the book at (someone) is 1932, from notion of judge sentencing a criminal from a law book full of possible punishments. To throw (one's) hat in the ring "issue a challenge," especially to announce one's candidacy, first recorded 1917. To throw up "vomit" is first recorded 1732.
throw (n.): "act of throwing," 1520s, from throw (v.). Wrestling sense is first attested 1819.
throw away (v.): late 14c., "to reject, cast from oneself," from throw (v.) + away. More literal meaning of "dispose of as useless, release from one's possession as unneeded" is first recorded 1520s. Throw-away (adj.) is first recorded 1924, originally of prices so low they amounted to giving away the merchandise; with reference to disposable goods, it is attested from 1969.
throwback (n.): "reversion to an ancestral type or character," 1888, from throw (v.) + back (adv.); earlier it meant "a reverse in a course or progress, a relapse" (1856).
thru: by 1839, altered (simplified) spelling of through.
thrum (v.): "play a stringed instrument," 1590s, from the noun (1550s), of imitative origin. Related: Thrummed; thrumming.
thruout: contraction of throughout.
thrush (n.1): type of songbird, Old English þyrsce (related to throstle), from Proto-Germanic *thruskjon (cf. Old Norse þröstr, Norwegian trost, Old High German drosca), from PIE *trozdo- (cf. Latin turdus, Lithuainian strazdas "thrush," Middle Irish truid, Welsh drudwy "starling," Old Church Slavonic drozgu, Russian drozdu).
thrush (n.2): throat disease, 1660s, probably from a Scandinavian source (cf. Norwegian, Danish trøske, Swedish torsk), but its roots and original meaning are unclear.
thrust (v.): late 12c., from Old Norse þrysta "to thrust, force," from Proto-Germanic *thrustijanan, perhaps from PIE *trud- "push, press" (see threat), but OED finds this derivation doubtful. The noun is recorded from 1510s; figurative sense of "principal theme, aim, point, purpose" is recorded from 1968.
thud (v.): Old English þyddan "to strike, thrust," of imitative origin. Sense of "hit with a dull sound" first recorded 1796. The noun is attested from 1510s.
thug (n.): 1810, "member of a gang of murderers and robbers in India who strangled their victims," from Marathi thag, thak "cheat, swindler," Hindi thag, perhaps from Sanskrit sthaga-s "cunning, fraudulent," possibly from sthagayati "(he) covers, conceals," from PIE root *(s)teg- "cover" (see stegosaurus). Transferred sense of "ruffian, cutthroat" first recorded 1839. The more correct Indian name is phanseegur, and the activity was described in English as far back as c.1665. Rigorously prosecuted by the British from 1831, they were driven from existence, but the process extended over the rest of the 19c.
Thule: northernmost part of the world, Old English, from Latin, from Greek Thyle "land six days' sail north of Britain" (Polybius). Identity is speculative; it came to be used in a transferred sense of "extreme limits of travel."
thumb (n.): Old English þuma, from West Germanic *thumon- (cf. Old Frisian thuma, Old Saxon, Old High German thumo, German Daumen, Dutch duim "thumb," Old Norse þumall "thumb of a glove"), literally "the stout or thick (finger)," from PIE *tum- "swell" (cf. Latin tumere "to swell," tumidus "swollen;" Avestan tuma "fat;" see thigh). For spelling with -b (attested from late 13c.), see limb.

To be under (someone's) thumb "be totally controlled by that person" is recorded from 1580s. Thumbs up (1887) and thumbs down (1906) were said to be from expressions of approval or the opposite in ancient amphitheaters, especially gladiator shows, where the gesture decided whether a defeated combatant was spared or slain. But the Roman gesture was merely one of hiding the thumb in the hand or extending it. Perhaps the modern gesture is from the usual coachmen's way of greeting while the hands are occupied with the reins.
thumb (v.): "to go through" (especially of printed material), 1930, from thumb (n.), though the related sense of "soil or wear by handling" dates from 1640s. Meaning "to hitchhike" is 1939; originally the thumb pointed in the direction one wished to travel. Related: Thumbed; thumbing. To thumb (one's) nose as an expression of derision is recorded from 1903.
thumbnail (n.): c.1600, from thumb (n.) + nail (n.). Meaning "drawing or sketch of a small size" (though usually not lierally the size of a thumbnail) is from 1852.
thumbtack (n.): tack with a broad, flat head which may be driven by pressure from the thumb, 1884, from thumb (n.) + tack (n.1).
thump (v.): 1530s, "to strike hard," probably imitative of the sound made by hitting with a heavy object (cf. East Frisian dump "a knock," Swedish dialectal dumpa "to make a noise"). Related: Thumped; thumping.
thump (n.): 1550s, from thump (v.).
thumping (adj.): "exceptionally large," colloquial, 1570s, present participle adjective from thump (v.).
thunder (n.): Old English þunor, from Proto-Germanic *thunraz (cf. Old Norse þorr, Old Frisian thuner, Middle Dutch donre, Dutch donder, Old High German donar, German Donner "thunder"), from PIE *(s)tene- "to resound, thunder" (cf. Sanskrit tanayitnuh "thundering," Persian tundar "thunder," Latin tonare "to thunder"). Swedish tordön is literally "Thor's din." The intrusive -d- is also found in Dutch and Icelandic versions of the word.
thunder (v.): Old English þunrian, from the source of thunder (n.). Figurative sense of "to speak loudly, threateningly, bombastically" is recorded from mid-14c. Related: Thundered; thundering.
thunderbolt (n.): mid-15c., from thunder (n.) + bolt (n.).
thunderclap (n.): late 14c., from thunder (n.) + clap (n.1).
thunderhead (n.): "high-piled cloud," 1861, from thunder (n.) + head (n.).
thunderous (adj.): 1580s, from thunder (n.) + -ous. Related: Thunderously.
thunderstorm (n.): 1650s, from thunder (n.) + storm (n.).
thunderstruck (adj.): 1610s, from thunder (n.) + past tense of strike. Originally figurative; the literal sense always has been rare.
thunk: sound of impact, attested from 1952, echoic.
Thursday (n.): Old English Þurresdæg, perhaps a contraction (influenced by Old Norse Þorsdagr) of Þunresdæg, literally "Thor's day," from Þunre, genitive of Þunor "Thor" (see Thor); from Proto-Germanic *thonaras daga- (cf. Old Frisian thunresdei, Middle Dutch donresdach, Dutch donderdag, Old High German Donares tag, German Donnerstag "Thursday"), a loan-translation of Latin Jovis dies "day of Jupiter."

Jupiter was identified with the Germanic Thor. The Latin word is the source of Italian giovedi, Old French juesdi, French jeudi, Spanish jueves, and is itself a loan-translation of Greek dios hemera "the day of Zeus."
thus (adv.): Old English þus "in this way," related to þæt "that" and this, but the exact connection and Proto-Germanic history are obscure. Cognate with Old Saxon and Old Frisian thus, Middle Dutch and Dutch dus. Colloquial adverb thusly first recorded 1865.
thusly (adv.): 1865, from thus + -ly (2). Perhaps originally a humorous or mocking over-correction of thus, it has gained some currency but still is frowned upon.
thwack (v.): "to hit hard with a stick," 1520s, of echoic origin. Related: Thwacked; thwacking. The noun is recorded from 1580s.
thwaite (n.): "cleared land," 1620s, from Old Norse or Old Danish þveit "a clearing, meadow, paddock," literally "cutting, cut-piece" (related to Old English þwitan "to cut, cut off"). Always a rare word and now obsolete, but frequently encountered in place names, but "It is unclear whether the base meaning was 'something cut off, detached piece of land,' or 'something cut down, felled tree' ..." [Cambridge Dictionary of English Place-Names].
thwart (adv.): c.1200, from Old Norse þvert "across," originally neuter of thverr (adj.) "transverse, across," cognate with Old English þweorh "transverse, perverse, angry, cross," from Proto-Germanic *thwerkhaz (cf. Middle Dutch dwers, Dutch dwars "cross-grained, contrary," Old High German twerh, German quer, Gothic þwairhs "angry"), altered (by influence of *thwer- "to turn") from *therkh-, from PIE *twork-/*twerk- "twist" (cf. Latin torquere "to twist," Sanskrit tarkuh "spindle," Old Church Slavonic traku "band, girdle," Old High German drahsil "turner," German drechseln "to turn on a lathe").
thwart (v.): "oppose, hinder," mid-13c., from thwart (adv.). Related: Thwarted; thwarting.
thy (pron.): possessive pronoun of 2nd person singular, late 12c., reduced form of þin (see thine), originally used before consonants except -h-. In 15c., used before vowels, too.
thyme (n.): plant of the mint family, late 14c., from Old French thym, tym (13c.), from Latin thymum, from Greek thymon, possibly from thyein "burn as a sacrifice," which would indicate the plant was used as incense.
thymine (n.): 1894, from thymic (1868, from Greek thyme; see thyme) + chemical suffix -ine (2).
thymus (n.): gland near the base of the neck, 1690s, Modern Latin, from Greek thymos "a warty excrescence," used of the gland by Galen, literally "thyme," probably so called because of a fancied resemblance to a bunch of thyme (see thyme).
thyroid (adj.): 1690s (in reference to both the cartilage and the gland), from Greek thyreoiedes "shield-shaped" (in khondros thyreoiedes "shield-shaped cartilage," used by Galen to describe the "Adam's apple" in the throat), from thyreos "oblong, door-shaped shield" (from thyra "door") + -eides "form, shape" (see -oid). The noun, short for thyroid gland, is recorded from 1849.