Definitions by Samus.

vulgar 

A rude term. Crudely indecent. Deficient in taste, delicacy, or refinement. Uncouth. Sometimes offensive, often used with sexual innuendo's.

Examples are talking about sexual things in public like:
Number one: screaming, "PENIS!"
Number two: "Don't be so vulgar Willie."

vulgar by Samus. January 6, 2006