half / haf/ • n. (pl. halves / havz/ ) either of two equal or corresponding parts into which something is or can be divided: the northern half of the island two and a half years | divided in half | reduced by half. ∎  either of two equal periods of time into which a sports game or a performance is divided. ∎ Baseball either of the two parts of one inning: the top half of the third. ∎  Golf a score for an individual hole that is the same as one's opponent's. ∎ short for halfback.• pron. & adj. an amount equal to a half: [as pron.] half of the lectures are delivered by him | [as adj.] the last half century. ∎  amounting to a part thought of as roughly a half: [as pron.] half of them are gate-crashers. • adv. to the extent of half: the glass was half full. ∎  [often in comb.] to a certain extent; partly: the chicken is half-cooked.PHRASES: a —— and a half inf. used to indicate that one considers a particular person or thing to be an impressive example of their kind: Aunt Edie was a woman and a half.at half cocksee half cock.go halves share something equally: she promised to go halves with him.half the battlesee battle.half a chance inf. the slightest opportunity: given half a chance, he can make anything work.half an eyesee eye.the half of it inf. the most important part or aspect of something: you don't know the half of it.half past one (two, etc.) thirty minutes after one (two, etc.) o'clock.half the timesee time.not do things by halves do things thoroughly or extravagantly.not half1. not nearly: he is not half such a fool as they thought.2. inf. not at all: the players are not half bad.too —— by half used to emphasize something bad: the idea seems too superstitious by half.

half half a loaf is better than no bread to have part of something is better than having nothing at all (compare something is better than nothing). The saying is recorded from the mid 16th century.
the half is better than the whole proverbial saying, mid 16th century, advising economy or restraint. The comparable ‘half is more than the whole’ is found in the writings of the Greek poet Hesiod (c.700 bc).
half mast the position of a flag which is being flown some way below the top of its staff as a mark of respect for a person who has died.
half the truth is often a whole lie something which is partially true can still convey a completely false impression; proverbial saying, mid 18th century.
one half of the world does not know how the other half lives proverbial saying, early 17th century, often used to comment on a lack of communication between neighbouring groups; the saying is found earlier in French, in Rabelais' Pantagruel (1532).

See also two boys are half a boy, do not meet troubles half-way, six of one and half a dozen of the other, well begun is half done at well2.

half adj. OE. h(e)alf = OS. (Du.) half, (O)HG. halb, ON. hálfr, Goth. halbs :- Gmc. *χalbaz; ult. connections doubtful. Applied to relatives that are such on one side only, as half-brother (XIV), half-sister (XIII), prob. — ON. Comp. halfpenny (XIV), in OE. healfpeniġwurð (see WORTH), whence †halpeny, ha'penny, †halp(w)orth, ha'p'orth. Also sb. †side; one of two equal parts. OE. h(e)alf = OS. halba, OHG. halba, ON. hálfa region, part, lineage, Goth. halba side, half.
So half adv. OE. in comb., e.g. healfcwicu ‘half-alive’, half-dead, healfrēad reddish, and in correl. use, e.g. healf man healf assa half man half ass (onocentaur). Hence halve divide into two. XIII.

half. If applied to a baluster or a column, it means engaged.