1. slang To be extremely mentally agitated or to lose control of one's emotions or thought processes; to have an emotional or mental breakdown. "Schiz" is an informal shortening of "schizophrenia." Potentially offensive. She must have stopped taking her meds, because she's started schizing out again lately. I heard he schized out after his wife left him.

2. offensive slang By extension, to get extremely upset; to freak out. My parents would schiz out if they found out I took the car without telling them! We'll get these issues sorted out before the product's launch—stop schizing out!