| Noun | 1. | functioning - process or manner of functioning or operating; "the power of its engine determine its operation"; "the plane's operation in high winds"; "they compared the cooking performance of each oven"; "the jet's performance conformed to high standards" Synonyms: performance, operation |
| Adj. | 1. | functioning - performing or able to perform its regular function; "a functioning flashlight" Antonyms: malfunctioning, nonfunctional - not performing or able to perform its regular function; "a malfunctioning valve" |