Answer: caver

AnswerCrossword Clue
CAVERSpelunker
CAVERLover of spelunking
CAVERUnderground explorer
CAVERSpeleologist
CAVERFan of spelunking
CAVERPotholer, this side of the pond
CAVERSpelunking aficionado
CAVERUnderground worker
CAVERStalactite spotter
CAVERSubterranean hobbyist
CAVERExplorer of sorts
CAVEROne who's frequently in the dark
caverperson who studies or explores caves
caverone that caves (to hollow out)