1.designed for or capable of a particular function or use;
a style of writing in which every word is functional
2.involving or affecting function rather than physiology;
functional deafness
3.relating to or based on function especially as opposed to structure;
the problem now is not a constitutional one; it is a functional one
4.fit or ready for use or service;
the toaster was still functional even after being dropped
5.designed for or adapted to a function or use;
functional education selects knowledge that is concrete and usable rather than abstract and theoretical
6.(of e.g. a machine) performing or capable of performing;
in running (or working) order