Dictionary.com
definitions

half

[haf, hahf]
noun, plural halves [havz, hahvz] /hævz, hɑvz/.
  1. one of two equal or approximately equal parts of a divisible whole, as an object, or unit of measure or time; a part of a whole equal or almost equal to the remainder.
  2. a quantity or amount equal to such a part (½).
  3. Sports. either of two equal periods of play, usually with an intermission or rest period separating them.Compare quarter(def 10).
  4. one of two; a part of a pair.
  5. Informal.
    1. half dollar.
    2. the sum of 50 cents: Four dimes and two nickels make a half.
  6. Baseball. either of the two units of play into which an inning is divided, the visiting team batting in the first unit and the home team batting in the second.
  7. Football. a halfback.
  8. British Informal.
    1. a half-crown coin.
    2. the sum of a half crown; two shillings, sixpence.
    3. a half pint: He ordered a half of ale.
adjective
  1. being one of two equal or approximately equal parts of a divisible whole: a half quart.
  2. being half or about half of anything in degree, amount, length, etc.: at half speed; half sleeve.
  3. partial or incomplete: half measures.
adverb
  1. in or to the extent or measure of half.
  2. in part; partly; incompletely: half understood.
  3. to some extent; almost: half recovered.
Idioms
  1. by half, by very much; by far: She was too talented by half for her routine role.
  2. half again as much/many, as much as 50 percent more: This mug holds half again as much coffee as the smaller one.
  3. half in two, Southern U.S. (chiefly Gulf States ). in or into two parts; in half: Cut the cake half in two.
  4. in half, divided into halves: The vase broke in half.
  5. not half,
    1. not at all; not really: His first attempts at painting are not half bad.
    2. half(def 20).
  6. not the half of, a significant yet relatively minor part of something that remains to be described in full: He accused them of being responsible for the error, and that's not the half of the story.Also not half of, not half.

Origin of half

before 900; Middle English; Old English h(e)alf; cognate with German Halb, Old Norse halfr, Gothic halbs

Synonyms for half

13. barely, somewhat, partially; sort of.

Grammar note

See well1.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for half's

half

noun plural halves (hɑːvz)
    1. either of two equal or corresponding parts that together comprise a whole
    2. a quantity equalling such a parthalf a dozen
  2. half a pint, esp of beer
  3. Scot a small drink of spirits, esp whisky
  4. sport the half of the pitch regarded as belonging to one team
  5. golf an equal score on a hole or round with an opponent
  6. (in various games) either of two periods of play separated by an interval (the first half and second half)
  7. a half-price ticket on a bus, train, etc
  8. short for half-hour
  9. short for halfpenny (def. 1)
  10. sport short for halfback
  11. obsolete a half-year period
  12. better half jocular a person's wife or husband
  13. by half by an excessive amount or to an excessive degreehe's too arrogant by half
  14. by halves (used with a negative) without being thorough or exhaustivewe don't do things by halves
  15. go halves (often foll by on, in, etc)
    1. to share the expenses (of something with one other person)
    2. to share the whole amount (of something with another person)to go halves on an orange
determiner
    1. being a half or approximately a halfhalf the kingdom
    2. (as pronoun; functioning as sing or plural)half of them came
adjective
  1. not perfect or complete; partialhe only did a half job on it
adverb
  1. to the amount or extent of a half
  2. to a great amount or extent
  3. partially; to an extent
  4. half two informal 30 minutes after two o'clock
  5. have half a mind to to have the intention of
  6. not half informal
    1. not in any wayhe's not half clever enough
    2. Britishreally; very; indeedhe isn't half stupid
    3. certainly; yes, indeed
Related formsRelated prefixes: bi-, demi-, hemi-, semi-

Word Origin for half

Old English healf; related to Old Norse halfr, Old High German halb, Dutch half
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for half's

half

Old English half, halb (Mercian), healf (W. Saxon) "side, part," not necessarily of equal division (original sense preserved in behalf), noun, adjective, and adverb all in Old English, from Proto-Germanic *khalbas "something divided" (cf. Old Saxon halba, Old Norse halfr, Old Frisian, Middle Dutch half, German halb, Gothic halbs "half"), perhaps from PIE (s)kel- "to cut."

Used also in Old English phrases as in modern German, to mean "one half unit less than," e.g. þridda healf "two and a half," literally "half third." The construction in two and a half, etc., is first recorded c.1200. Of time, in half past ten, etc., first attested 1750; in Scottish, the half often is prefixed to the following hour, as in German (e.g. halb elf "ten thirty"). To go off half-cocked "speak or act too hastily" (1833) is in allusion to firearms going off prematurely.

Online Etymology Dictionary, © 2010 Douglas Harper
Idioms and Phrases with half's

half

In addition to the idioms beginning with half

  • half a heart, with
  • half a loaf is better than none
  • half a mind
  • half of it
  • half the battle

also see:

  • at half-mast
  • better half
  • by half
  • glass is half full
  • go halfway
  • go off (half-cocked)
  • in half
  • not bad (half bad)
  • six of one, half dozen of the other
  • time and a half
  • with half an eye

Also see underhalfwayhalves.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.