Officium (plural officia) is a Latin word with various meanings, including service, (sense of) duty, courtesy, ceremony and the likes.

However this article is mainly concerned with the meaning of an office (the modern word stems for it) or bureau in the sense of a dignitaries staff of (administrative and other) collaborators, each of which was called officialis (hence the modern official) after it. An official is, in the primary sense, someone who holds an office in an organisation, of any kind. ...