old boiled rice moistened with rice vinegar, usually shaped into bite-size pieces and topped with raw seafood (nigiri-zushi) or formed into a long seaweed-wrapped roll, often around strips of vegetable or raw fish, and sliced into bite-size pieces (maki-zushi)
to assume a facial expression indicating pleasure, favor, or amusement, but sometimes derision or scorn, characterized by an upturning of the corners of the mouth.