The Collaborative International Dictionary of English v.0.48:

Caravansary \Car`a*van"sa*ry\, n.; pl. Caravansaries. [F.
   caravans['e]rai, fr. Per. karw[=a]nsar[=a]["i]; karw[=a]n
   caravan + -sar[=a]["i] palace, large house, inn.]
   A kind of inn, in the East, where caravans rest at night,
   being a large, rude, unfurnished building, surrounding a
   court. [Written also caravanserai and caravansera.]
   [1913 Webster]

WordNet (r) 3.0 (2006):

caravanserai
    n 1: an inn in some eastern countries with a large courtyard
         that provides accommodation for caravans [syn:
         caravansary, caravanserai, khan, caravan inn]