spelunker

n. 爱好探索洞穴的人

speed-indicator, speed-up, speedboat, speedily, speediness, speeding, speedometer, speedway, speedwell, speedy, speleological (also spelaeological), speleologist (also spelaeologist), speleology (also spelaeology), spell, spellbinder, spellbinding, spellbound, speller, spelling, spelt, spend, spend...time (in) doing, spender, spending, spendthrift, spent, sperm, sperm whale, spermaceti, spermatozoon, spermicidal, spermicide, spew, sphagnum, sphere, spherical, spherically, spheroid, sphincter, sphinx,