Punk is also a term originating in the African American community that is used to refer to men who exhibit feminine traits. It is quite derogatory and similar to the word faggot.
In the Spike Lee movie School Daze, the fraternity does a number where they shout "punk, punk, fag, fag, punk, punk, fag, fag" repeatedly. This scene has been used in other movies, most notably Marlon Riggs's Tounges Untied, which portrays the general acceptance of homophobia of the African American community.