| n. | 1. | One who, or that which, hums; one who applauds by humming. |
| 2. | (Zool.) A humming bird. |
| Noun | 1. | hummer - a singer who produces a tune without opening the lips or forming words |
| 2. | hummer - (baseball) a pitch thrown with maximum velocity; "he swung late on the fastball"; "he showed batters nothing but smoke" |