speleology
Longman Dictionary of Contemporary English 5++LDOCE 5++spe·le·ol·o·gy /ˌspiːliˈɒlədʒi $ -ˈɑːl-/ noun [uncountable] technical 1. DSODLO British English the sport of walking and climbing in caves 洞穴攀爬运动 SYN American English spelunking2. SGthe scientific study of caves 洞穴学 —speleologist noun [countable]
spe·le·ol·o·gy nounChineseSyllable

