The Collaborative International Dictionary of English v.0.48:

Mahayana \Mahayana\ n.
   1. a major school of Buddhism teaching social concern and
      universal salvation, found in China; Japan; Tibet; Nepal;
      Korea; and Mongolia.
      [WordNet 1.5]

   2. one of two great schools of Buddhist doctrine emphasizing
      a common search for universal salvation esp through faith
      alone; chiefly in China; Tibet; Japan.
      [WordNet 1.5]

WordNet (r) 3.0 (2006):

Mahayana
    n 1: a major school of Buddhism teaching social concern and
         universal salvation; China; Japan; Tibet; Nepal; Korea;
         Mongolia
    2: one of two great schools of Buddhist doctrine emphasizing a
       common search for universal salvation especially through
       faith alone; the dominant religion of China and Tibet and
       Japan [syn: Mahayana, Mahayana Buddhism]