Entries linking to head-gear
Old English heafod "top of the body," also "upper end of a slope," also "chief person, leader, ruler; capital city," from Proto-Germanic *haubid (source also of Old Saxon hobid, Old Norse hofuð, Old Frisian haved, Middle Dutch hovet, Dutch hoofd, Old High German houbit, German Haupt, Gothic haubiþ "head"), from PIE root *kaput- "head."
Modern spelling is early 15c., representing what was then a long vowel (as in heat) and remained after pronunciation shifted. Of rounded tops of plants from late 14c. Meaning "origin of a river" is mid-14c. Meaning "obverse of a coin" (the side with the portrait) is from 1680s; meaning "foam on a mug of beer" is first attested 1540s; meaning "toilet" is from 1748, based on location of crew toilet in the bow (or head) of a ship.
Synechdochic use for "person" (as in head count) is first attested late 13c.; of cattle, etc., in this sense from 1510s. As a height measure of persons, from c. 1300. Meaning "drug addict" (usually in a compound with the preferred drug as the first element) is from 1911.
To be over (one's) head "beyond one's comprehension" is by 1620s. To give head "perform fellatio" is from 1950s. Phrase heads will roll "people will be punished" (1930) translates Adolf Hitler. Head case "eccentric or insane person" is from 1966. Head game "mental manipulation" attested by 1972.
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").
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" first attested 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.