definition of
functional

[1] #1 functional a. designed for or capable of a particular function or use; "a style of writing in which every word is functional"; "functional architecture". wn

[2] #2 functional a. involving or affecting function rather than physiology; "functional deafness". wn

[3] #3 functional a. relating to or based on function especially as opposed to structure; "the problem now is not a constitutional one; it is a functional one"; "delegates elected on a functional rather than a geographical basis". wn

[4] #4 functional s. [usable, useable, operable, operational] fit or ready for use or service; "the toaster was still functional even after being dropped"; "the lawnmower is a bit rusty but still usable"; "an operational aircraft"; "the dishwasher is now in working order". wn

[5] #5 functional s. [running, operative, working] (of e.g. a machine) performing or capable of performing; "in running (or working) order"; "a functional set of brakes". wn