APARTMENTS TO LET, phr. (common).1. Empty-headed; foolish; crazy: see BALMY.
2. (old).Said of a widow; also of a woman given to prostitution: e.g., She lets out her fore room and lies backward (RAY and GROSE).
1809. MALKIN, Gil Blas [ROUTLEDGE], 191. A theatrical lady may change her lover as often as her petticoat and rivals came back in crowds ready to bargain on the mere report of my being TO LET.