The Collaborative International Dictionary of English v.0.48:

Courtyard \Court"yard\ (k?rt"y?rd`), n.
   A court or inclosure attached to a house.
   [1913 Webster]

WordNet (r) 3.0 (2006):

courtyard
    n 1: an area wholly or partly surrounded by walls or buildings;
         "the house was built around an inner court" [syn: court,
         courtyard]

Moby Thesaurus II by Grady Ward, 1.0:

25 Moby Thesaurus words for "courtyard":
   arena, cincture, close, confine, container, coop, court, curtilage,
   delimited field, enclave, enclosure, field, fold, ground, list,
   pale, paling, park, pen, quad, quadrangle, square, theater, toft,
   yard