demi-

a combining form appearing in loanwords from French meaning “half” (demilune), “lesser” (demitasse), or sometimes used with a pejorative sense (demimonde); on this model, also prefixed to words of English origin (demigod).

Origin

< French, combining form representing demi (adj.; also noun and adv.) < Vulgar Latin *dīmedius, for Latin dīmidius half, equivalent to dī- di-² + medius middle

British Dictionary definitions for demi-

demi-

prefix

half: demirelief Compare hemi-, semi- (sense 1)

of less than full size, status, or rank: demigod

Word Origin

via French from Medieval Latin dīmedius, from Latin dīmīdius half, from dis- apart + medius middle

Word Origin and History for demi-

word-forming element meaning "half, half-sized, partial," early 15c., from Old French demi "half" (12c.), from Late Latin dimedius, from Latin dimidius "half, one-half," which contains the elements dis- "apart" (see dis-) + medius "middle" (see medial).

demi- in Medicine

demi- pref.
Half: demilune.