vulgar vs common

vulgar is not a noun while common is a noun.

Word	Noun	Adjective	Verb	Adverb
vulgar	No	Yes	No	No
common	Yes	Yes	No	No

As adjectives, vulgar and common are synonyms defined as:

Other synonyms of vulgar include plebeian, unwashed.

As adjectives, vulgar and common are synonyms defined as:

Other synonyms of vulgar include coarse, rough-cut, uncouth.

As adjectives, vulgar and common are synonyms defined as:

vulgar and common: being or characteristic of or appropriate to everyday language

Other synonyms of vulgar include vernacular.

vulgar (noun)	common (noun)
	a piece of open land for recreational use in an urban area

vulgar (adjective)	common (adjective)
conspicuously and tastelessly indecent	having no special distinction or quality; widely known or commonly encountered; average or ordinary or usual
of or associated with the great masses of people	belonging to or participated in by a community as a whole; public
lacking refinement or cultivation or taste	commonly encountered
being or characteristic of or appropriate to everyday language	of low or inferior quality or value
	being or characteristic of or appropriate to everyday language
	of or associated with the great masses of people
	to be expected; standard
	common to or shared by two or more parties
	lacking refinement or cultivation or taste