Source : Webster's Revised Unabridged Dictionary (1913)

Boudoir \Bou*doir"\, n. [F., fr. bouder to pout, be sulky.]
   A small room, esp. if pleasant, or elegantly furnished, to
   which a lady may retire to be alone, or to receive intimate
   friends; a lady's (or sometimes a gentleman's) private room.
   --Cowper.

Source : WordNet®

boudoir
     n : a lady's bedroom or private sitting room