noun

• (obsolete) An insane person; a lunatic; a madman.
  "Lets follow the old Earle, and get the bedlom To lead him where he would, his rogiſh madnes Allows it ſelfe to any thing."
• (obsolete) A lunatic asylum; a madhouse.
  "It was a ſhrewd ſaying of the old Monk, That two kind of Priſons would ſerve for all offenders in the World, an Inquiſition and a Bedlam: If any man ſhould deny the Being of a God and the Immortality of the Soul, ſuch a one ſhould be put into the firſt of these, the Inquiſition, as being a deſperate Heretick; but if any man ſhould profeſs to believe theſe things, and yet allow himſelf in any known wickedneſs, ſuch a one ſhould be put into Bedlam; becauſe there cannot be a greater folly and madneſs, than for a man in matters of greateſt moment and concernment to act againſt his beſt Reaſon and Underſtanding, and by his Life to contradict his Belief."

name

• (informal) Bethlem Royal Hospital, a famous psychiatric hospital, now located in Bromley, South London.