operable vs functional

operable and functional both are adjectives.

Word	Noun	Adjective	Verb	Adverb
operable	No	Yes	No	No
functional	No	Yes	No	No

As adjectives, operable and functional are synonyms defined as:

Other synonyms of operable include operational, usable, useable.

operable (adjective)	functional (adjective)
capable of being treated by surgical operation	designed for or capable of a particular function or use
usable for a specific purpose	involving or affecting function rather than physiology
fit or ready for use or service	relating to or based on function especially as opposed to structure
	(of e.g. a machine) performing or capable of performing
	designed for or adapted to a function or use
	fit or ready for use or service