cavern
🇺🇸
/ˈkævərn/
🇬🇧
/ˈkævən/
A large, natural underground space that is open and has no roof.
The explorers discovered a hidden cavern filled with sparkling crystals.
探險者們發現了一個隱藏的洞穴,裡面充滿了閃閃發光的水晶。