Definition of "Functional" :

adjective: designed for or capable of a particular function or use

"A style of writing in which every word is functional."

adjective: (of e.g. a machine) performing or capable of performing

"A functional set of brakes."

adjective: involving or affecting function rather than physiology

"Functional deafness."

adjective: designed for or adapted to a function or use

"Functional education selects knowledge that is concrete and usable rather than abstract and theoretical."

adjective: fit or ready for use or service

"The toaster was still functional even after being dropped."

adjective: relating to or based on function especially as opposed to structure

"The problem now is not a constitutional one; it is a functional one."