n. Gram. a word governing (and usu. preceding) a noun or pronoun and expressing a relation to another word or element, as in: 'the man on the platform', 'came after dinner', 'what did you do it for?'. prepositional adj. prepositionally adv.
[ ME f. L praepositio f. praeponere praeposit- (as PRAE-, ponere place) ]