What does FUNCTIONAL mean?

adjective

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”