a word or group of words, e.g. by, on, from, or on account of, that links a noun, pronoun, etc to another part of the sentence, as in ‘Put it on the floor’ and ‘Where did they come from?’
prepositional adj
prepositionally adv
[Middle English preposicioun from Latin praeposition-, praepositio, from praeponere to put in front, from prae- + ponere to put]