noun

1. in some languages, a relation or function word, as English in, by, for, with, to, etc., that connects a lexical word, usually a noun or pronoun, or a syntactic construction, to another element of the sentence, as to a verb (Ex.: he went to the store), to a noun (Ex.: the sound of loud music), or to an adjective (Ex.: good for her)
2. any construction of similar function (Ex.: in back of, equivalent to behind)

Etymology: ME preposicioun < L praepositio (< praepositus, pp. of praeponere < prae-, before + ponere, to place: see pre- & position): transl. of Gr prothesis, prothesis