func·tus of·fi·cio \|fəŋ(k)təsəˈfishēˌō\adjective Etymology: Latin, having performed his duty, having served its purpose : of no further official authority or legal efficacy — used of an officer no longer in office or of an instrument, power, or agency that has fulfilled the purpose of its creation < once exercised, their power of approval or disapproval is functus officio — U.S. Fed. Supplement >