Shortened as 'OTT', it pertains to anyone that has crossed the limits of sanity or anger in a conversation, relationship, or situation, or gone crazy to the point of danger.
Its roots come from the trenches of WWI, where anyone who had lost their mind from war trauma and battle would disobey orders and climb over the top of the protective trenches, leading to immediate death.
"Damn, he just went over the top yesterday!"
"People say she went over the top, but noone really knows."
(adj.) Somethin' so crazy, it's CUH-RAZY!
Homie 1: "You crazy."
Homie 2: "Well, you cuh-razy!"
Homie 3: "Shut it."