functioning adjective 2noun 2forms 3 adjective2 •Functional, working.The other factions believe that those who are Factionless are nomads and outcasts. But they are actually a fully functioning community. — 2015 •(euphemistic) Of a person, mentally disabled but still able to survive in wider society.Oh, he looked pretty functioning to me. noun2 •Action of the verb function. •Manner by which something functions; the workings. formsfunctionings · more functioning · most functioning