1.Pertaining to, or connected with, a function or duty; official.
2.(Pathology, Physiol.) Pertaining to the function of an organ or part, or to the functions in general; involving or affecting function rather than physiology; as, functional deafness; a functional disease. See functional disease, below. (wns=2)
3.Designed for or capable of a particular function or use; as, a style of writing in which every word is functional; functional architecture. (wns=1)
4.Fit or ready for use or service; useable; in working order; as, the toaster was still functional even after being dropped; the lawnmower is a bit rusty but still functional. Antonym of out of order and nonfunctional. (wns=4 & 6)
5.Designed to emphasize practical utility rather than artistic or aesthetic purposes; as, functional education selects knowledge that is concrete and usable rather than abstract and theoretical; functional architecture; an amateurish device, crude but functional.