That's a nine Share definition Flag That's a cop/cop car/any police vehicle. Said to alert people about the arrival or sight of the police. Homie1: Smoking dope Homie2:*sees a cop car* Homie2: That's a nine *All homies run away* That's a nine by 999_Yash_999 October 11, 2020 0 0 Get merch Get the That's a nine mug. Buy Now — $32.95 See more merch