pusher vs drug dealer

pusher and drug dealer both are nouns.

Word	Noun	Adjective	Verb	Adverb
pusher	Yes	No	No	No
drug dealer	Yes	No	No	No

As nouns, pusher and drug dealer are synonyms defined as:

Other synonyms of pusher include drug peddler, drug trafficker, peddler.

pusher (noun)	drug dealer (noun)
a small vehicle with four wheels in which a baby or child is pushed around	an unlicensed dealer in illegal drugs
a sandal attached to the foot by a thong over the toes
someone who pushes
an unlicensed dealer in illegal drugs
one who intrudes or pushes himself forward