Real Dictionary

preposition
countable noun: A preposition is a word such as 'by', 'for', 'into', or 'with' which usually has a noun group as its object.

preposition in American English
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

preposition in American English 1
noun: any member of a class of words found in many languages that are used before nouns, pronouns, or other substantives to form phrases functioning as modifiers of verbs, nouns, or adjectives, and that typically express a spatial, temporal, or other relationsh

preposition in American English 2
transitive verb: to position in advance or beforehand

preposition in British English
noun: a word or group of words used before a noun or pronoun to relate it grammatically or semantically to some other constituent of a sentence