DuckCorp Dico

Found one definition

1.                 From WordNet (r) 3.0 (2006):
                   
   
   
                   
                     
   hummer
       n 1: a singer who produces a tune without opening the lips or
            forming words
       2: (baseball) a pitch thrown with maximum velocity; "he swung
          late on the fastball"; "he showed batters nothing but smoke"
          [syn: fastball, heater, smoke, hummer, bullet]