The Collaborative International Dictionary of English v.0.48:

Cloakroom \Cloak"room`\, n.
   A room, attached to any place of public resort, where cloaks,
   overcoats, etc., may be deposited for a time.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

coatroom \coatroom\ n.
   a room where coats and other articles can be left
   temporarily; -- called also cloakroom.

   Syn: cloakroom.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

cloakroom
    n 1: a private lounge off of a legislative chamber
    2: a room where coats and other articles can be left temporarily
       [syn: cloakroom, coatroom]