crypt

noun6

1. •
   An underground vault.
2. •
   Especially: one beneath a church that is used as a burial chamber.

   • She turned and waved a hand to him, she cried a word, but he didn't hear it, it was a lost word. A sable wraith she was in the parkland, fading away into the dolorous crypt of winter. — 1922
3. •
   A small pit or cavity in the surface of an organ or other structure.

   • Sometimes, too much foreign material can get caught in the crypts, leading to frequent infections. — 2015
4. •
   Any of the genus Cryptocoryne of aquatic plants of southern and southeastern Asia.
5. •
   Any of the genus Cryptopus of orchids of Madagascar and Mauritius.
6. •
   (no longer used) A cave or cavern.