1590, one of the three fundamental functions of trigonometry, from tangent (adj.). From 1650s as "a tangent line." Figurative use of on a tangent is from 1771.

1580s, "capable of being touched," from French tangible and directly from Late Latin tangibilis "that may be touched," from Latin tangere "to touch," from PIE root *tag- "to touch, handle." Sense of "material" (as in tangible reward) is first recorded 1610s; that of "able to be realized or dealt with" is from 1709. Related: Tangibly.

mid-13c., dragoun, a fabulous animal common to the conceptions of many races and peoples, from Old French dragon and directly from Latin draconem (nominative draco) "huge serpent, dragon," from Greek drakon (genitive drakontos) "serpent, giant seafish," apparently from drak-, strong aorist stem of derkesthai "to see clearly," from PIE *derk- "to see" (source also of Sanskrit darsata- "visible;" Old Irish adcondarc "I have seen;" Gothic gatarhjan "characterize;" Old English torht, Old High German zoraht "light, clear;" Albanian dritë "light").

Perhaps the literal sense is "the one with the (deadly) glance." The young are dragonets (c. 1300). Fem. form dragoness is attested from 1630s. Obsolete drake (n.2) "dragon" is an older borrowing of the same word, and a later form in another sense is dragoon. Used in the Bible generally for creatures of great size and fierceness; it translates Hebrew tannin "a great sea-monster," and tan, a desert mammal now believed to be the jackal.

c. 1200, "fighting equipment, armor and weapons," probably from Old Norse gørvi (plural gørvar) "apparel, gear," related to görr, gørr, gerr "skilled, accomplished; ready, willing," and to gøra, gørva "to make, construct, build; set in order, prepare," a very frequent verb in Old Norse, used in a wide range of situations from writing a book to dressing meat.

This is from Proto-Germanic *garwjan "to make, prepare, equip" (source also of Old English gearwe "clothing, equipment, ornament," which may be the source of some uses; Old Saxon garwei; Dutch gaar "done, dressed;" Old High German garo "ready, prepared, complete," garawi "clothing, dress," garawen "to make ready;" German gerben "to tan"). Old English glossed Latin apparatus with gearcung.

From early 14c. as "wearing apparel, clothes, dress;" also "harness of a draught animal; equipment of a riding horse." From late 14c. as "equipment generally; tools, utensils," especially the necessary equipment for a certain activity, as the rigging of a sailing ship. It was used generically as an affix in 16c. canting slang for "thing, stuff, material."

Meaning "toothed wheel in machinery" is attested by 1520s; specific mechanical sense of "parts by which a motor communicates motion" is from 1814; specifically of a vehicle (bicycle, automobile, etc.) by 1888. Slang for "male sex organs" from 1670s.