Functional :: Functional (a.) Pertaining to, or connected with, a function or duty; official..
Functional :: Functional (a.) Pertaining to the function of an organ or part, or to the functions in general..
Functionally :: Functionally (adv.) In a functional manner; as regards normal or appropriate activity.
Functionary :: Functionary (n.) One charged with the performance of a function or office; as, a public functionary; secular functionaries..
Functionate :: Functionate (v. i.) To execute or perform a function; to transact one's regular or appointed business.