Pintle

A pintle is part of a primitive pintle-and-gudgeon hinge system. The gudgeon is a single collar and the pintle is a single pin that fits into the collar. The pintle, pointing up, might be attached to the static side of the hinge and the gudgeon would be slipped down over the pintle (pictured). Alternately, the gudgeon might be attached to the static side, and the pintel would be slipped down into the gudgeon.

 Is the rudder secured on its pintles?

Why Homer Matters by Adam Nicolson

While this seems to be a specialized, mostly nautical, term, the etymology highlights the varied nature of etymological paths into the English lexicon. The antecedent is none other than penis, as might be expected from its nautical heritage. When not being used to mount (pun intended) rudders or guns, pintle might still be used to refer to an actual penis.