locum vs locum tenens

locum and locum tenens both are nouns.

Word	Noun	Adjective	Verb	Adverb
locum	Yes	No	No	No
locum tenens	Yes	No	No	No

As nouns, locum and locum tenens are synonyms defined as:

locum and locum tenens: someone (physician or clergyman) who substitutes temporarily for another member of the same profession

locum (noun)	locum tenens (noun)
someone (physician or clergyman) who substitutes temporarily for another member of the same profession	someone (physician or clergyman) who substitutes temporarily for another member of the same profession