A potholer is a person who does potholing: the British sport of climbing down deep holes in the ground to explore caves underneath. The word names the explorer, not the sport itself. You hear it in Britain; Americans more often say caver. It is a hobby-and-sport word, a bit specialist, not everyday chat unless someone in the family does it. Though actually, the pothole here is not the broken bit of road that splashes your bike. In this sport a pothole is a natural shaft in limestone country, a vertical way into the dark. A potholer wears a helmet and lamp and is ready to squeeze, climb, and get wet. People who only fill road holes are not potholers.

探洞的人、洞穴探險者（英式；美式較常說 caver）