functional

UK: /ˈfʌŋkʃ^ənəl/ US: /ˈfʌŋkʃənəl/ ,(fungk′shə nl)

WordReference Random House Learner's Dictionary of American English © 2025

func•tion•al /ˈfʌŋkʃənəl/   adj. 

1. of or relating to a function or functions.
2. capable of functioning:
   When will the ventilating system be functional again?
3. having or serving a useful purpose:
   This screen is functional as well as decorative.
4. Psychology of or relating to improper function without known cause:
   [before a noun] a functional disorder.

func•tion•al•i•ty /ˌfʌŋkʃəˈnælɪti/  n. [uncountable]
func•tion•al•ly, adv. See -funct-.

WordReference Random House Unabridged Dictionary of American English © 2025

func•tion•al  (fungk′shə nl), adj. 

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. Architecture, Furniture Also, func′tion•al•is′tic. (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. Medicine without a known organic cause or structural change:
   a functional disorder.
   Cf. organic (def. 5).
6. Mathematics pertaining to an algebraic operation:
   a functional symbol.
7. Linguistics (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.

n. 

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

• function + -al¹ 1625–35

func′tion•al′i•ty, n. 
func′tion•al•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

functional / ˈfʌŋkʃən^əl/ adjective

1. of, involving, or containing a function or functions
2. practical rather than decorative; utilitarian
3. capable of functioning; working
4. affecting a function of an organ without structural change

ˈfunctionally adverb