What does HAMMER mean?

noun

1. the part of a gunlock that strikes the percussion cap when the trigger is pulled
2. a hand tool with a heavy rigid head and a handle; used to deliver an impulsive force by striking
3. the ossicle attached to the eardrum
4. a light drumstick with a rounded head that is used to strike such percussion instruments as chimes, kettledrums, marimbas, glockenspiels, etc.
5. a heavy metal sphere attached to a flexible wire; used in the hammer throw
6. a striker that is covered in felt and that causes the piano strings to vibrate
7. a power tool for drilling rocks
8. the act of pounding (delivering repeated heavy blows)“the sudden hammer of fists caught him off guard”