Source : Webster's Revised Unabridged Dictionary (1913)

Stateroom \State"room`\, n.
   1. A magnificent room in a place or great house.

   2. A small apartment for lodging or sleeping in the cabin, or
      on the deck, of a vessel; also, a somewhat similar
      apartment in a railway sleeping car.

Source : WordNet®

stateroom
     n : a guest cabin