Locum tenens

A locum tenens is a person who stands in for, i.e., takes the place of, another member of the same profession on a temporary basis. The expression is particularly likely to be used of a doctor, pharmacist, or clergyman who acts as a temporary substitute for another member of the same profession when the latter has, e.g., gone on holiday or been granted sick leave.

The expression locum tenens is nowadays rarely used in full: a locum tenens is almost always referred to simply as a locum.

Locum tenens is a Latin expression meaning ‘(a person) holding the place (of another)', and takes a Latin plural, locum tenentes.

Note on pronunciation: The expression locum tenens is pronounced in English with a long vowel in the first syllable of each word, 'LOW-kum TEE-nenz', (IPA: /'ləʊ kəm 'tiː nɛnz/), even though in the original Latin both words have a short vowel in these syllables, LOCK-em TEN-enz, (IPA: / 'lɒ kəm 'tɛ nɛnz/).

The Latin locum tenens is also, through French, the origin of the English word lieutenant.