sledgehammer vs hammer

sledgehammer and hammer both are nouns.

Word	Noun	Adjective	Verb	Adverb
sledgehammer	Yes	No	Yes	No
hammer	Yes	No	Yes	No

As nouns, hammer is a hypernym of sledgehammer; that is, hammer is a word with a broader meaning than sledgehammer:

sledgehammer: a heavy long-handled hammer used to drive stakes or wedges
hammer: a hand tool with a heavy rigid head and a handle; used to deliver an impulsive force by striking

As verbs, hammer is a hypernym of sledgehammer; that is, hammer is a word with a broader meaning than sledgehammer:

sledgehammer (noun)	hammer (noun)
a heavy long-handled hammer used to drive stakes or wedges	the act of pounding (delivering repeated heavy blows)
	a hand tool with a heavy rigid head and a handle; used to deliver an impulsive force by striking
	a power tool for drilling rocks
	a striker that is covered in felt and that causes the piano strings to vibrate
	a light drumstick with a rounded head that is used to strike such percussion instruments as chimes, kettledrums, marimbas, glockenspiels, etc.
	the part of a gunlock that strikes the percussion cap when the trigger is pulled
	a heavy metal sphere attached to a flexible wire; used in the hammer throw
	the ossicle attached to the eardrum

sledgehammer (verb)	hammer (verb)
beat with a sledgehammer	beat with or as if with a hammer
	create by hammering