noun-
Literally meaning *'J'-Category*
—>California prison slang<—

A commonly used phrase in California prisons indicating a mentally unstable person, or someone whom is intentionally or unintentionally acting mentally unstable. Most commonly refers to a person who has been involuntarily admitted to mental health services, but also may be used as a derogatory adjective.

Derived from inmate mental health codes found in Article 9 and inmate classification administrative determinants found in Article 10 of the California Department of Corrections and Rehabilitation's Title 15, Rules and Regulations:
->"Article 9, section 3364.2 (j) The judicial hearing for an order authorizing the involuntary administration of psychiatric medication to an inmate shall be conducted by an ALJ"

Note: the 2020 Title 15, Article 10, section 3375.2 (17) has been revised to remove the 'J' designation and replaced with a 'PSY' three-letter code.

Alternate spellings:

Jay-Cat

jaycat
"Hey man, you see that guy over there? Yeah just don't interact with him, he's a j-cat for sure."
"Oh yeah, that guy Ronny just came back from Classification Committee and he's now a confirmed j-cat."
"I was grocery shopping yesterday and some j-cat came up to me and just started incoherently blabbering."
"Yo, Billy just acts like a j-cat so he can get free psych meds."
by Pankakke.exe November 7, 2021
(Prison/Jail Term) Any person who is mentally unstable or requires psyche drugs to maintain.
That fool over there talking to himself, walking like a chicken is a J Cat.
by Wood Dawger October 3, 2005
Otherwise known as "Category J" in the California Penal Code, it refers to an inmate deemed too mentally unstable to remain in General Population.
"Motherfucker went J Cat on someone in the yard; now he's in ADSEG."
by J. Knox April 23, 2008
An individual who is looped up on psychiatric medications.
by Doug March 28, 2005
anymore of this and im going to go j-cat.
by homerower April 14, 2006
a person who doesn't know how to act in jail (when in jail)
These new bitches in are tank are straight j-cats.
That fool keeps cattin off.
by Maguire Corrections October 11, 2010
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.
Breh, that nigga Marcus he coo n shit but ever since that nigga ate dem shrooms, that nigga been acting like a straight J-Cat. Real Talk
by imastr8gee May 29, 2015