riff /ˈrɪf/
  即興重複段
  Riff
       n 1: a Berber living in northern Morocco [syn: Riffian]
       2: a jazz ostinato; usually provides a background for a solo
          improvisation
       v 1: look through a book or other written material; "He thumbed
            through the report"; "She leafed through the volume"
            [syn: flick, flip, thumb, riffle, leaf]
       2: play riffs