'Preposition' definitions:

Definition of 'preposition'

From: WordNet
noun
A function word that combines with a noun or pronoun or noun phrase to form a prepositional phrase that can have an adverbial or adjectival relation to some other word
noun
(linguistics) the placing of one linguistic element before another (as placing a modifier before the word it modifies in a sentence or placing an affix before the base to which it is attached)

Definition of 'Preposition'

From: GCIDE
  • Preposition \Prep`o*si"tion\, n. [L. praepositio, fr. praeponere to place before; prae before + ponere to put, place: cf. F. pr['e]position. See Position, and cf. Provost.] [1913 Webster]
  • 1. (Gram.) A word employed to connect a noun or a pronoun, in an adjectival or adverbial sense, with some other word; a particle used with a noun or pronoun (in English always in the objective case) to make a phrase limiting some other word; -- so called because usually placed before the word with which it is phrased; as, a bridge of iron; he comes from town; it is good for food; he escaped by running. [1913 Webster]
  • 2. A proposition; an exposition; a discourse. [Obs.] [1913 Webster]
  • He made a long preposition and oration. --Fabyan. [1913 Webster]