Functioning
Part of speech: adjective
Definition: working
Part of speech: noun
Definition: action of the verb to function The manner in something functions; the workings
Part of speech: verb
Definition: To have a function.
Functional
Part of speech: noun
Definition: A function that takes a function as its argument; More precisely: A function y=f(x) whose argument x varies in a space of (real valued, complex valued) functions and whose value belongs to a monodimensional space. An example: the definite integration of integrable real functions in a real interval.
Part of speech: adjective
Definition: In good working order.Useful; serving a purpose, fulfilling a functionOnly for fuctional purposes, notably in architectureHaving semantics defined purely in terms of mathematical functions, without side-effects.Of a disease, such that its symptoms cannot be referred to any appreciable lesion or change of structure; opposed to organic disease, in which the organ itself is affected.
Example sentence: When you come to a hotel room, you want it to be grand, functional and beautiful. But you don't want things that are not useful. Sometimes you go to hotels and there are all these frames and pictures of people you don't know, and you end up hiding everything in the drawer, and then housekeeping come and put it out again.