The word 'valve' entered English in the late 14th century from the Latin 'valva', meaning 'a folding door, a section of a door'. This Latin term is related to 'volvere', meaning 'to roll', suggesting the concept of a turning or hinging mechanism. The anatomical sense, referring to a bodily structure that opens and closes like a door, was established by the early 17th century. The modern mechanical sense, denoting a device for regulating flow, developed naturally from this core idea of a movable part that controls passage.

The word 'valve' is a simplex word borrowed as a whole from Latin. It does not contain separable, productive morphemes in modern English spelling.