cavern
/ˈkævən/noun
1- a cave, or a chamber in a cave, typically a large one（尤指大的）洞穴, 山洞; （洞穴的）深凹处, 深处。
1.1
- used in similes and comparisons to refer to a vast, dark space大而黑之处（用于比喻、比较中）：
a dark cavern of a shop.
一家像一个黑沉沉的山洞似的商店。
词源
late Middle English: from Old French caverne or from Latin caverna, from cavus 'hollow'. Compare with CAVE1.