late 15c., pariel, "rope or chain that fixes the middle of a yard to a mast," from parel "equipment" (c. 1400), earlier "apparel" (early 14c.), a shortening of apparel (n.).
c. 1300, "personal fighting equipment, body armor," also "armor or trappings of a war-horse," from Old French harnois, a noun of broad meaning: "arms, equipment; harness; male genitalia; tackle; household equipment" (12c.), of uncertain origin, perhaps from Old Norse *hernest "provisions for an army," from herr "army" (see harry (v.)) + nest "provisions" (see nostalgia). Non-military sense of "fittings for a beast of burden" is from early 14c. German Harnisch "harness, armor" is the French word, borrowed into Middle High German. The Celtic words are believed to be also from French, as are Spanish arnes, Portuguese arnez, Italian arnese. Prive harness (late 14c.) was a Middle English term for "sex organs."
"horse's harness, etc.," 1924, shortening of tackle (n.) in sense of "equipment." Tack in a non-equestrian sense as a shortening of tackle is recorded in dialect from 1777.
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.
Old English here-geatwe (plural) "military equipment, army-gear," from here "army" (see harry (v.)) + geatwe, from Proto-Germanic *gatawja- "equipment," from Germanic root *taw- "to make, manufacture" (see taw (v.)). An Anglo-Saxon service of weapons, loaned by the lord to his retainer and repayable to him upon the retainer's death; sense transferred by 13c. to a feudal due upon the death of a tenant, payable to his lord in beasts.
"fashion of dress," 1620s, from earlier sense "person's outward demeanor" (c. 1600), originally "elegance, stylishness" (1590s), from French garbe "graceful outline, gracefulness, comeliness" (Modern French galbe) or directly from Italian garbo "grace, elegance, pleasing manners, " which is from Old High German gar(a)wi "dress, equipment, preparation," or some other Germanic source, from Proto-Germanic *garwi- "equipment; adornment" (see gear (n.)).