The Collaborative International Dictionary of English v.0.48:

Crypt \Crypt\ (kr[i^]pt), n. [L. crypta vault, crypt, Gr.
   kry`pth, fr. kry`ptein to hide. See Grot, Grotto.]
   1. A vault wholly or partly under ground; especially, a vault
      under a church, whether used for burial purposes or for a
      subterranean chapel or oratory.
      [1913 Webster]

            Priesthood works out its task age after age, . . .
            treasuring in convents and crypts the few fossils of
            antique learning.                     --Motley.
      [1913 Webster]

            My knees are bowed in crypt and shrine. --Tennyson.
      [1913 Webster]

   2. (Anat.) A simple gland, glandular cavity, or tube; a
      follicle; as, the crypts of Lieberk["u]hn, the simple
      tubular glands of the small intestines.
      [1913 Webster]

WordNet (r) 3.0 (2006):

crypt
    n 1: a cellar or vault or underground burial chamber (especially
         beneath a church)

The Free On-line Dictionary of Computing (19 January 2023):

crypt

   Unix command to perform encryption and decryption.