Do you know ghouls from goblins and ghosts?
"scene of mad confusion," 1660s, from colloquial pronunciation of "Hospital of Saint Mary of Bethlehem" in London, founded 1247 as a priory, mentioned as a hospital 1330 and as a lunatic hospital 1402; converted to a state lunatic asylum on dissolution of the monasteries in 1547. It was spelled Bedlem in a will from 1418, and Betleem is recorded as a spelling of Bethlehem in Judea from 971.
the first asylum for the mentally ill in England. It is currently located in Beckenham, Kent. The word bedlam came to be used generically for all psychiatric hospitals and sometimes is used colloquially for an uproar.