Functus Officio
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
Lat Having fulfilled the function, discharged the office or accomplished the purpose, and therefore of no further force or authority. Applied to an officer whose term has expired, and who has consequently no further official authority; and also to an instrument, power, agency, etc., which has fulfilled the purpose of its creation, and is therefore of no further virtue or effect.