Etymology: Middle English hed, from Old English hēafod; akin to Old High German houbit head, Latin caput
Date: before 12th century
1: the upper or anterior division of the animal body that contains the brain, the chief sense organs, and the mouth 2 a: the seat of the intellect :mind<two heads are better than one>b: a person with respect to mental qualities <let wiser heads prevail>c: natural aptitude or talent <a good head for figures>d: mental or emotional control :poise<a level head>e:headache 3: the obverse of a coin —usually used in plural 4 a:person, individual<count heads>bpluralhead: one of a number (as of domestic animals) 5 a: the end that is upper or higher or opposite the foot <the head of the table><head of a sail>b: the source of a stream c: either end of something (as a drum) whose two ends need not be distinguished 6:director, leader: as a:headmasterb: one in charge of a division or department in an office or institution 7 a:capitulum 2 b: the foliaged part of a plant especially when consisting of a compact mass of leaves or close fructification <a head of lettuce> 8 a: the leading element of a military column or a procession b:headway 9 a: the uppermost extremity or projecting part of an object :topb: the striking part of a weapon, tool, or implement c: the rounded proximal end of a long bone (as the humerus) d: the end of a muscle nearest the origin e: the oval part of a printed musical note 10 a: a body of water kept in reserve at a height; also: the containing bank, dam, or wall b: a mass of water in motion 11 a: the difference in elevation between two points in a body of fluid b: the resulting pressure of the fluid at the lower point expressible as this height; broadly: pressure of a fluid 12 a: the bow and adjacent parts of a ship b: a ship's toilet; broadly:toilet 3 13: the approximate length of the head of a horse <won by a head> 14: the place of leadership, honor, or command <at the head of her class> 15 a (1): a word or series of words often in larger letters placed at the beginning of a passage or at the top of a page in order to introduce or categorize (2): a separate part or topic b: a portion of a page or sheet that is above the first line of printing 16: the foam or scum that rises on a fermenting or effervescing liquid (as beer) 17 a: the part of a boil, pimple, or abscess at which it is likely to break b: culminating point of action :crisis<events came to a head> 18 a: a part or attachment of a machine or machine tool containing a device (as a cutter or drill); also: the part of an apparatus that performs the chief function or a particular function b: an electromagnet used as a transducer in magnetic recording for recording on, reading, or erasing a magnetic medium (as tape or a disk) 19: an immediate constituent of a construction that can have the same grammatical function as the whole (as man in “an old man”, “a very old man”, or “the man in the street”) 20 a: one who uses a drug —often used in combination <pothead>b: a devoted enthusiast :aficionado —often used in combination <computerhead> 21often vulgar:fellatio, cunnilingus —usually used with give
— by the head: drawing the greater depth of water forward
— over one's head1: beyond one's comprehension or competence <the most awful intellectual detail, all of it over my head — E. B. White> 2: so as to pass over one's superior standing or authority <went over my head to complain>