Old English heafod "top of the body," also "upper end of a slope," also "chief person, leader, ruler; capital city," from Proto-Germanic *haubudam (cf. 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 *kaput- "head" (cf. Sanskrit kaput-, Latin caput "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" 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 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 1979. Head game "mental manipulation" attested by 1972. To have (one's) head up (one's) ass is attested by 1978.
"most important, principal, leading," c.1200, from head (n.). Old English heafod was used in this sense in compounds.
"clever, alert," 1952, from warning cry "heads up!" (i.e. "look up!"), attested by 1939.
head (hěd)
n.
The uppermost or forwardmost part of the human body, containing the brain and the eyes, ears, nose, mouth, and jaws.
The analogous part of various vertebrate and invertebrate animals.
The pus-containing tip of an abscess, a boil, or a pimple.
The rounded proximal end of a long bone.
The end of a muscle that is attached to the less movable part of the skeleton.
A warning of some impending danger or need to be alert: Heads up, for heaven's sake (1940s+)
acid freak, airhead, balloonhead, bananahead, beanhead, bighead, a big head, bite someone's head off, blockhead, blubberhead, bonehead, bubblehead, buckethead, bullhead, cheesehead, chickenhead, chiphead, chowderhead, chucklehead, clunkhead, cokehead, deadhead, doo-doo head, dumbhead, fathead, flathead, garbage head, get one's head out of one's ass, ginhead, give head, good head, go soak yourself, hardhead, hash head, have a hole in one's head, have one's head pulled, have rocks in one's head, one's head is up one's ass, head shop, headshrinker, hit the nail on the head, hophead, hothead, in over one's head, jarhead, juicehead, knucklehead, lunkhead, meathead, metal head, meth head, musclehead, mush-head, muttonhead, need someone or something like a hole in the head, noodlehead, numbhead, off one's nut, off the top of one's head, out of one's head, over one's head, pighead, pillhead, pinhead, pointhead, pointy-head, potato-head, pothead, puddinghead, pumpkinhead, rockhead, rocks in one's head, rotorhead, saphead, shithead, soft in the head, sorehead, stand on one's head, talking head, use one's head, weedhead, where someone's head is at, woodenhead, woodenhead, yell one's head off
Clever; alert; shrewd: They're playing real heads-up football (1940s+)
modifier: Daschle was on Mitchell's heads-up list for good reason
nounA warning; a meeting where warning is given: blamed Young for not giving regents a ''heads up'' about the controversy/ Altman called a brief heads-up designed to tell the White House what procedures the RFC would follow (1990s+)