pneumatic hammer vs jackhammer

pneumatic hammer and jackhammer both are nouns.

Word	Noun	Adjective	Verb	Adverb
pneumatic hammer	Yes	No	No	No
jackhammer	Yes	No	No	No

As nouns, pneumatic hammer and jackhammer are synonyms defined as:

Other synonyms of pneumatic hammer include air hammer.

pneumatic hammer (noun)	jackhammer (noun)
a hammer driven by compressed air	a hammer driven by compressed air