Thole-pin is a term typically used to describe a peg or pin that is used as a fulcrum to support an oar or a rowlock in a boat or a ship. This term may seem a bit rare, but there are still other words or phrases that can aptly be used in place of thole-pin. Some of these synonyms include peg, rowlock, oarlock, pin, pivot, fulcrum, hinge, swivel, and support. Ultimately, these words all refer to a tool or device that provides stability and support to the rower, allowing him or her to maneuver the boat efficiently.