officium

Officium is a Latin noun (neuter) meaning duty, service, function, or office. It is used to designate both personal obligations and public roles, and it is the etymological source of the English words office, official, and officialdom. In classical Rome, officium referred to the formal duties attached to a public office or priestly function, and could denote a public service performed by magistrates, officials, or priests.

In Christian usage, officium came to denote a liturgical service performed by clergy. By the medieval and early modern periods, Officium Divinum, or the Divine Office, described the set of daily prayers recited at fixed times of day. In the Catholic tradition this framework evolved into what is now called the Liturgy of the Hours, the daily cycle of prayers, readings, and hymns observed by various religious communities and, to a lesser extent, by laypeople.

Today the term officium remains common mainly in historical, liturgical, or scholarly contexts. It also occurs in music as a title: the 1994 collaboration between the saxophonist Jan Garbarek and the Hilliard Ensemble, Officium, and its follow-up, Officium Novum. More broadly, officium underlines the Latin roots of modern concepts of public duty and organizational function.