early 14c., from Anglo-French mortuarie "gift to a parish priest from a deceased parishioner," from Medieval Latin mortuarium, noun use of neuter of Late Latin adjective mortuarius "pertaining to the dead," from Latin mortuus, past participle of mori "to die" (see mortal, adj.). Meaning "place where bodies are kept temporarily" first recorded 1865, a euphemism for earlier deadhouse.

1510s, "pertaining to death," from Late Latin mortuarius "of the dead," from Latin mortuus "dead" (see mortuary, n.).