spelunker \spih-LUNK-er\ noun
Meaning : one who makes a hobby of exploring and studying caves

"What's that?"
"I said, I'm going to have to climb back round the other way."
"Okay, so, should I wait here?"
"Sure. I'll only be a few minutes."
Jenny had never wanted to be here. It was wet and dark. Her socks were sticking to her feet, and she could feel mud in the bottom of her shoes. That's what she got for dating a spelunker, she thought.