common vs vulgar

common is a noun but vulgar is not a noun.

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

As adjectives, common and vulgar are synonyms defined as:

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

Other synonyms of common include vernacular.

As adjectives, common and vulgar are synonyms defined as:

Other synonyms of common include plebeian, unwashed.

As adjectives, common and vulgar are synonyms defined as:

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

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

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