The word 'tenon' entered English in the late 14th century from the Old French 'tenon', meaning "a tenon, projection, stump". This Old French term derived from the verb 'tenir', meaning "to hold", which itself originates from the Latin 'tenēre', with the core meaning "to hold, keep, maintain". The semantic logic is direct: the tenon is the part of the joint that is "held" securely within the mortise. This reflects the fundamental principle of the mortise and tenon joint, one of the oldest and strongest woodworking connections, where the tenon is gripped firmly by the surrounding wood of the mortise.

The word is a simplex loanword from French. Its spelling and form are treated as a single unit in modern English.