The word 'tenet' entered English in the early 17th century directly from Latin, where 'tenet' means "he/she holds." It is the third person singular present indicative of the verb 'tenēre,' meaning "to hold." This Latin verb originates from the Proto-Indo-European root ten-, meaning "to stretch, extend." The semantic journey from the physical act of "holding" to an abstract principle one "holds" is clear and logical. Thus, a tenet is figuratively a belief or doctrine that a person or group holds onto and maintains.

This word is a simplex loanword from Latin. It does not contain separable, productive morphemes in modern English spelling.