The Collaborative International Dictionary of English v.0.48:
Bordel \Bor"del\, Bordello \Bor*del"lo\, n. [F. bordel, orig. a little hut, OF. borde hut, cabin, of German origin, and akin to E. board,n.See. Board, n.] A brothel; a bawdyhouse; a house devoted to prostitution. [Obs.] --B. Jonson. [1913 Webster]