Source : Webster's Revised Unabridged Dictionary (1913)

Robe-de-chambre \Robe`-de-cham"bre\, n. [F., lit., a chamber
   gown.]
   A dressing gown, or morning gown.

Source : WordNet®

robe-de-chambre
     n : a robe worn before dressing or while lounging [syn: {dressing
         gown}, {lounging robe}]
     [also: {robes-de-chambre} (pl)]