functional: Meaning and Definition of

func•tion•al

1. of or pertaining to a function or functions: functional difficulties in the administration.
2. capable of operating or functioning: When will the ventilating system be functional again?
3. having or serving a utilitarian purpose; capable of serving the purpose for which it was designed: functional architecture; a chair that is functional as well as decorative.
4. (of a building or furnishing) constructed or made according to the principles of functionalism or primarily as a direct fulfillment of a material need.
5. without a known organic cause or structural change:Cf. organic (def. 5). a functional disorder.
6. pertaining to an algebraic operation: a functional symbol.
7. (of linguistic analysis, language teaching, etc.) concerned with the communicative role of language rather than, in addition to, or as the framework for its formal structure.

1. a function that has a domain whose elements are functions, sets, or the like, and that assumes numerical values.