A crypt is a vault for burying the dead and is often underneath or part of a church building. Crypt rhymes with "gripped," and if you saw a corpse come out of a crypt, you would definitely be gripped with terror.
While a coffin is a rectangular box used for burying dead people underground, a crypt is often an elaborate stone or marble vault that's above ground. Some cultures believe in investing in large, decorated crypts to honor the dead, while others choose simpler chambers very close together for keeping family members near, even in death. A crypt can inspire scary thoughts of lids popping and doors opening for the walking dead, but that's due mostly to the widespread crypt scenes in horror movies. Mostly.