crypt (n.) Look up crypt at
early 15c., "grotto, cavern," from Latin crypta "vault, cavern," from Greek krypte (short for krypte kamara "hidden vault"), fem. of kryptos "hidden," verbal adjective from kryptein "to hide," from PIE root *krau- "to conceal, hide" (source also of Old Church Slavonic kryjo, kryti "to hide"). Meaning "underground burial vault or chapel in a church" first attested 1789.