The Collaborative International Dictionary of English v.0.48:

Doorway \Door"way`\, n.
   The passage of a door; entrance way into a house or a room.
   [1913 Webster]

WordNet (r) 3.0 (2006):

doorway
    n 1: the entrance (the space in a wall) through which you enter
         or leave a room or building; the space that a door can
         close; "he stuck his head in the doorway" [syn: doorway,
         door, room access, threshold]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "doorway":
   French door, archway, back door, barway, bulkhead,
   carriage entrance, cellar door, cellarway, door, doorjamb,
   doorpost, entrance, entranceway, entry, entryway, front door, gate,
   gatepost, gateway, hatch, hatchway, lintel, porch, portal,
   porte cochere, postern, propylaeum, pylon, scuttle, side door,
   stile, storm door, threshold, tollgate, trap, trap door, turnpike,
   turnstile