cavern (n.)youdaoicibaDictYouDict[cavern 词源字典]
late 14c., from Old French caverne (12c.) "cave, vault, cellar," from Late Latin caverna "cave," from Latin cavus "hollow" (see cave (n.)). In Old English such a land feature might be called an eorðscræf.[cavern etymology, cavern origin, 英语词源]