a Japanese dish consisting of small cakes of cold cooked rice flavored with vinegar, typically garnished with strips of raw or cooked fish, cooked egg, vegetables, etc.
See sushi in American Heritage Dictionary 4
su·shi
noun
Cold cooked rice dressed with vinegar that is shaped into bite-sized pieces and topped with raw or cooked fish, or formed into a roll with fish, egg, or vegetables and wrapped in seaweed.