J-CAT is an word now used in street slang that originated in the U.S. Federal and State prison systems as an acrynym with stood for J-Category inmates or J-CAT which is s housing unit for sex offenders. Most inmates detest sex offenders and do not associate with them. The word J-CAT became synonymous with someone you did not like, someone you thought was shadey or someone who was acting gay. The word then bleed into the streets from the prisons by released inmates. Over time the definition has broadened but the core of the word remains, it always indicates a negative feeling. J-CAT can also be used when someone is trying to duck, dodge or avoid someone, or someone who is consistently flaking and selling wolf tickets. In this scenario it is often shorten as in "Nigga where you been? "You been cattin off on me.. Whatchu scared of my nigga? Hit me back!" J-CAT is also used to describe a dope feen, some one who is now different, weird after ecsesive drug use.