noun.
An outer room that opens into another room, often used as a waiting room.
The Century Dictionary and Cyclopedia
noun.
A smaller room before a chief apartment, to which access is had through it; especially, a waiting-room used for the temporary reception of visitors, etc.; an antechamber.
the GNU version of the Collaborative International Dictionary of English
noun.
A room before, or forming an entrance to, another; a waiting room.