1. 1. The uppermost or forwardmost part of the body of a vertebrate, containing the brain and the eyes, ears, nose, mouth, and jaws.
   2. The analogous part of an invertebrate organism.
   3. The length or height of such a part: The horse lost by a head. She is two heads taller than he is.
2. The seat of the faculty of reason; intelligence, intellect, or mind: I did the figuring in my head.
3. Mental ability or aptitude: She has a good head for mathematics.
4. Freedom of choice or action: Give the child his head and see how well he solves the problems.
5. Slang.
   1. A habitual drug user. Often used in combination: a dopehead.
   2. An enthusiast. Often used in combination: a chilihead.
6. A person considered foolish or contemptible. Often used in combination: a chowderhead.
7. A portrait or representation of a person's head.
8. (used with a sing. verb) The side of a coin having the principal design, often of the head of a famous person, and the date. Often used in the plural with a singular verb.
9. Informal. A headache: had a bad head early this morning.
10. 1. An individual; a person: charged five dollars a head.
    2. pl., head. A single animal: 20 head of cattle.
11. 1. A person who leads, rules, or is in charge; a leader, chief, or director: the head of the corporation.
    2. A headmaster or headmistress.
12. The foremost or leading position: marched at the head of the parade.
13. A headwaiter.
14. 1. The difference in depth of a liquid at two given points.
    2. (Abbr. hd.) The measure of pressure at the lower point expressed in terms of this difference.
    3. The pressure exerted by a liquid or gas: a head of steam.
    4. The liquid or gas exerting the pressure.
15. The froth or foam that rises to the top in pouring an effervescent liquid, such as beer.
16. The tip of an abscess, boil, or pimple, in which pus forms.
17. A turning point; a crisis: bring matters to a head. See synonyms at crisis.
18. 1. A projection, weight, or fixture at the end of an elongated object: the head of a pin; a head of land overlooking the harbor.
    2. The working end of a tool or implement: the head of a hammer.
    3. The part of an explosive device that carries the explosive; a warhead.
    4. The part of a stringed instrument where the strings are wound; a tuning head.
    5. A tuning machine.
19. Anatomy.
    1. The rounded proximal end of a long bone: the head of the femur.
    2. The end of a muscle that is attached to the less movable part of the skeleton.
20. 1. An attachment to or part of a machine that holds or contains the operative device.
    2. The magnetic head of a tape recorder or VCR.
    3. The device in a magnetic disk or tape drive that enables it to read data from and write data to the disk or tape.
21. A rounded compact mass, as of leaves or buds: a head of cabbage.
22. Botany. A flower head.
23. The uppermost part; the top: Place the appropriate name at the head of each column.
24. The end considered the most important: sat at the head of the table.
25. Either end of an object, such as a drum, whose two ends are interchangeable.
26. Nautical.
    1. The forward part of a vessel.
    2. The top part or upper edge of a sail.
27. A toilet, especially on a ship.
28. A passage or gallery in a coal mine.
29. (Abbr. hd.) Printing.
    1. The top of a book or page.
    2. A headline or heading.
    3. A distinct topic or category: under the head of recent Spanish history.
30. Headway; progress.
31. Linguistics. The word in a construction that has the same grammatical function as the construction as a whole and that determines relationships of concord to other parts of the construction or sentence in which the construction occurs.
32. Vulgar Slang. Oral sex.

1. Of, relating to, or intended for the head. Often used in combination: headshaking; headwrap.
2. Foremost in rank or importance: the head librarian.
3. Placed at the top or the front: the head name on the list.
4. Slang. Of, relating to, or for drugs or drug users.

1. To be in charge of; lead: The minister headed the committee.
2. To be in the first or foremost position of: Collins heads the list of job candidates.
3. To aim, point, or turn in a certain direction: headed the team of horses up the hill.
4. To remove the head or top of.
5. Sports. To hit (a soccer ball) in the air with one's head.
6. To provide with a head: head each column with a number; headed the flagpole with a golden ball.

1. To proceed or go in a certain direction: head for town.
2. To form a head, as lettuce or cabbage.
3. To originate, as a stream or river; rise.

head off

1. To block the progress or completion of; intercept: Try to head him off before he gets home. The town headed off the attempt to build another mall.

have a big (or swelled) head

1. To be overly self-confident or conceited.

1. Far superior to: head and shoulders above her colleagues in analytical capability.

1. Rolling, as in a somersault: tripped and fell head over heels.
2. Completely; hopelessly: head over heels in love.

1. To remain calm; remain in control of oneself.

1. To lose one's poise or self-control.

1. Insane; crazy.

1. As one's responsibility or fault: If this project fails, it's on your head.

1. Beyond one's comprehension.
2. Beyond one's financial means.

1. To consult and plan together: Let's put our heads together and solve this problem.

[Middle English, from Old English hēafod.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.