functor (n.)

A term sometimes used in WORD classification for words and BOUND MORPHEMES whose role in language is largely or wholly grammatical, such as PREPOSITIONS, ARTICLES, PRONOUNS, CONJUNCTIONS. Several such terms relate to this notion (e.g. FUNCTION WORD, GRAMMATICAL word, FORM word, EMPTY word); all contrast with the LEXICAL words in a language, which carry the main SEMANTIC content.

In FORMALIZED analyses, a functor is an EXPRESSION which DENOTES a FUNCTION. In CATEGORIAL GRAMMAR, it is the SYNTACTIC CATEGORY of such an expression, generally represented by a pair of category LABELS separated by a slash.