A mortuary is a room or area, often in a hospital, where dead bodies are kept. You can also use the word mortuary to talk about a funeral home.
When a person dies in a hospital, his body is usually moved to a mortuary before an autopsy takes place. A mortuary is also where a body is kept until it's buried or cremated. Another word for a mortuary is a morgue, which is more commonly used in the United States. In the 1500's, mortuary was used as an adjective meaning "pertaining to death," from the Latin root word mortuus, or "dead."