Officio

Officio is a Latin noun meaning “of office” or “duty,” derived from officium (duty or service, also used for office). In Latin grammar, officio appears in the ablative or dative forms, depending on construction. In modern English, the word is mainly encountered in the fixed Latin phrase ex officio, meaning by virtue of one’s office. The phrase denotes a status or function that arises from holding another position, rather than from a separate appointment.

In practice, ex officio describes a person’s membership or authority that automatically attaches to a particular office. For example, a chairperson may be an ex officio member of a committee, or a head of state may be ex officio a member of certain councils. The term is common in government, corporate governance, academia, and ecclesiastical settings, where it helps distinguish roles that follow from office from those created by direct appointment or election. Some legal and administrative documents use ex officio in statutory language, while others render the idea in plain English as “by virtue of office.”

Usage notes: officio alone is rarely used in contemporary English outside specialized Latin phrases; ex officio is the standard form. The concept is closely related to, but distinct from, ex oficio in some Romance languages, where separate terms may exist for “by office” or “by duty.” In legal and organizational writing, ex officio remains a concise way to express automatic status tied to holding an office.