noun.
Originally, a room set apart from the great hall for private conference and conversation; a withdrawing-room. It finally became the public room of a private house. See def. 3.
noun.
An apartment in a convent, asylum, inn, hospital, hotel, boarding-school, or the like, in which the inmates are permitted to meet and converse with visitors.
noun.
A room in a private house set apart for the conversational entertainment of guests; a reception-room; a drawing-room; also, in Great Britain, the common sitting-room or keeping-room of a family, as distinguished from a drawing-room intended for the reception of company.
noun.
Vulgarly, any room more or less “elegantly” or showily furnished or fitted up, and devoted to some specific purpose: as, tonsorial parlors; a photographer's parlors; oyster parlors; misfit parlors.