# Dictionary Definition

half adj

1 consisting of one of two equivalent parts in
value or quantity; "a half chicken"; "lasted a half hour" [syn:
half(a)]

2 partial; "gave me a half smile"; "he did only a
half job" [syn: half(a)]

3 (of siblings) related through one parent only;
"a half brother"; "half sister" [ant: whole]

### Noun

1 one of two equal parts of a divisible whole;
"half a loaf"; "half an hour"; "a century and one half" [syn:
one-half]

2 in various games or performances: either of two
periods of play separated by an interval adv : partially or to the
extent of a half; "he was half hidden by the bushes" [also:
halves (pl)]

# User Contributed Dictionary

## English

### Etymology

healf ('half'); as a noun, 'half', 'side', 'part'; akin to Old Saxon, Old Friesian, and Dutch half, German halb, Swedish half, Danish halv, Icelandic hālfr and Gothic 𐌷𐌰𐌻𐌱𐍃 (halbs). Compare halve, behalf.## Dutch

### Adjective

# Extensive Definition

One half is the irreducible
fraction resulting from dividing one by
two
(½), or any number by its double; multiplication by one
half is equivalent to division by
two. It is the fraction occurring most often in mathematical
equations, recipes, measurements, etc. Half can also be said to be
one part of something divided into two equal parts.

For instance, the area S of a
triangle is computed

- S = ½ × base × perpendicular height.

One half also figures in the
formula for calculating figurate
numbers, such as triangular
numbers and pentagonal
numbers:

- ½ × n [(s - 2) n - (4 - s)]

and in the formula for
computing magic constants for magic
squares

- M2(n) = ½ × [n (n2 + 1 )].

One half has two different
decimal expansions, the
familiar 0.5 and the recurring
0.49999999... It has a similar pair of expansions in any even base.
It is a common trap to believe these expressions represent distinct
numbers: see the
proof that 0.999... equals 1 for detailed discussion of a
related case.

One half is also:

- One of the few fractions to get a key of its own on typewriters. It also gets its own point in some early extensions of ASCII at 171; and in Unicode, it gets its own code point at 189 in the C1 Controls and Latin-1 Supplement block, and a cross-reference in the Number Forms block, which contains some other fractions.
- One of the few fractions which is commonly expressed in natural languages by suppletion rather than regular derivation; compare English one half with regular formations like one sixth from six.

## See also

half in German:
Moiety

half in Spanish: ½ (un
medio)

half in Esperanto:
Duono

half in French: Un
demi

half in Hebrew:
חצי

half in Dutch:
Half

half in Japanese:
1/2

half in Polish:
Moiety

half in Sicilian:
Mitati

half in Chinese:
一半

# Synonyms, Antonyms and Related Words

allotment, allowance, big end, bigger
half, bisection,
bit, bite, budget, chunk, commission, contingent, cut, deal, destiny, distributional, distributive, dividend, dole, end, equal, equal share, equidistance, even stephen,
fate, fifty percent,
fifty-fifty, half-and-half, halfway, halfway house, halver, halvers, helping, hemisphere, interest, lot, measure, mediety, meed, mess, mid-distance, midcourse, middle distance,
midway, modicum, moiety, one-and-a-half, part, partial, particular, partly, per capita, per head,
percentage, piece, portion, pro rata, proportion, proportional, proportionate, prorated, quantum, quota, rake-off, ration, respective, segment, semicircle, semisphere, several, share, slice, small share, stake, stock