office [ME] In the Middle Ages office meant a duty that went with someone’s position or employment. It goes back ultimately to Latin officium ‘performance of a task’, which in turn comes from the combined elements of opus ‘work’ (source of English opus in the early 19th century and of operation [LME]) and facere ‘to do’. The sense of ‘a place for business’ is recorded from the later Middle Ages. Someone officious [LME] was originally obliging or efficient in carrying out their office. The word developed its modern negative sense at the end of the 16th century.