Used to describe someone with questionable mental stability.
Marcus: Hey Bruva, let’s go throw down wif dem niggas on da court.
DeRon: Naw son, them straight up 730 niggas. I ain’t even playin’.
Marcus: Fo reals? Shit. Ima holla achu later then, son.
“730” is derived from a psychological exam that all inmates in the prison system must take. It was used to determine the sanity level of the prisoners. Once some of the inmates were released and information about the test was shared, it became a street term in Queens and other areas to call someone insane.
It was first used in the media in the DMX song “Niggas Done Started Somethin’”