Dictionary.com/vulgar:

vulgar (VUL-ger) adjective

1. Crudely indecent.
2. 1. Deficient in taste, delicacy, or refinement.
   2. Marked by a lack of good breeding; boorish. See Synonyms at common.
   3. Offensively excessive in self-display or expenditure; ostentatious: the huge vulgar houses and cars of the newly rich.
3. Spoken by or expressed in language spoken by the common people; vernacular: the technical and vulgar names for an animal species.
4. Of or associated with the great masses of people; common.

Source: The American Heritage® Dictionary of the English Language, Fourth Edition
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