hard–core

1a :  of, relating to, or being part of a hard core hard–core poverty the hard–core unemployedb :  confirmed, die-hard hard–core rock fans a hard–core liberal

2 of pornography :  containing explicit descriptions of sex acts or scenes of actual sex acts — compare soft-core

3 :  characterized by or being the purest or most basic form of something :  fundamental a room gussied up in hard–core French provincial style — John Canaday