Originally derived from slurring the words Ridiculous and Legit together. Basically meaning that something is pretty ridiculous but is definitely legitimate.
Lamar:"Hey man look at that trick. She does that to every guy she dates."
Trent:"Yeeeaaahy man she's mos def playin him."
Lamar:"you got too admit tho she's pretty regit man."
Trent:"Yeah when are these foosgon get a clue."
Pronunciation(reh-jit) a word meaning something is so legitimate (Authentic; genuine) that it's retarded (Uncomprehending to the brain).
Guy 1: "Wow, this band is retardedly legit!!"
Guy 2: "No dude, this shit's regit."