One who willingly engages in ass play with a partner who has not first cleaned their anus and rectum with an enema or at least a finger and a lot of soap.
"It isn't necessary to be a chunk spelunker if you've got a colon hydrotherapist in the neighborhood"
by become_the_mountain March 23, 2006
Eddie got so trashed on Friday that he went all chunk spelunker on that 900lb slab of white beef. When he regained conciousness the next morning, he had to pull on the rope to find his way out. He hasn't been the same since.
by respect the teacher August 13, 2009
One who engages in anal play in the hope of getting an unexpected dividend on their probe caused by improper preparation and/or hygiene...
Max likes to dig deep in his partner's ass in the hope of coming out with a plum; he is a true chunk spelunker...
by JPnEB May 28, 2008