thread (n.)

"to hurl, fling, propel," early 13c., throuen, from Old English þrawan "to twist, turn, writhe, curl," (past tense þreow, past participle þrawen, geþrawen), from Proto-Germanic *threw- (source also of Old Saxon thraian, Middle Dutch dræyen, Dutch draaien, Old High German draen, German drehen "to turn, twist;" not found in Scandinavian or Gothic). This is reconstructed to be from PIE root *tere- (1) "to rub, turn," with derivatives referring to twisting.

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 "twist, turn" senses in the English word survived in dialect and technical use.

As "emit, send forth" beams of light, etc., late 14c. In wrestling, "cast or pull to the ground," c. 1300. As "deliver" (a blow, punch) from late 15c. The sense of "put by force" (as in throw in jail) is attested by 1550s.

Of a horse shedding itself of a rider, from 1530s. Of a domestic animal, "produce offspring, drop, give birth," by 1845. The meaning "confuse, flabbergast" is from 1844.

The transitive meaning "lose (a race, game) deliberately, allow another to win unnecessarily or by prior agreement" is by 1868, U.S. colloquial. To throw (someone) off "confuse by a false scent, put off the right track" is from 1891.

To throw a party was in U.S. college slang by 1916. To throw a switch is by 1930. 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 on "don" (armor, clothes) is from late 14c. To throw off "cast off or away, get rid of hurriedly or forcibly" is by 1610s. To throw up is from early 15c. in reference to a sigh; by 1670s as "give up, resign, abandon, cease to do;" by 1732 as "to vomit." To throw together "put together hastily or roughly" is from 1711.

late 14c., thred-bare, of garments, "worn-out, shabby," from thread (n.) + bare (adj.). The notion is of "having the nap worn off," leaving the foundation threads exposed. Figurative sense of "deficient" is by early 15c.

*terə-, Proto-Indo-European root meaning "to rub, turn," with derivatives referring to twisting, also to boring, drilling, piercing; and to the rubbing of cereal grain to remove the husks, and thus to threshing.

It forms all or part of: atresia; attorn; attorney; attrition; contour; contrite; detour; detriment; diatribe; drill (v.) "bore a hole;" lithotripsy; return; septentrion; thrash; thread; thresh; throw; threshold; trauma; trepan; tribadism; tribology; tribulation; trite; triticale; triturate; trout; trypsin; tryptophan; turn.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit turah "wounded, hurt;" Greek teirein "to rub, rub away;" Latin terere "to rub, thresh, grind, wear away," tornus "turning lathe;" Old Church Slavonic tiro "to rub;" Lithuanian trinu, trinti "to rub," Old Irish tarathar "borer," Welsh taraw "to strike."