Location in Tombstone Arizona where, in 1881, Wyatt Earp, Doc Holliday, Virgil and Morgan Earp fought te McLaurys and Clantons in a gunfight, standoff-style.
In modern day terms, a rough part of a town can be referred to as the "OK corral", or a place where 'gangster' fights often take place. Can also be used as a state of emotion, i.e. the two children were ok corral- or on the verge of a standoff.
I'd rather be A-ok then OK corral. Damn, I am so gangster! Look at these gats I be packing! Shiiiiit!