Wagwan - Translated to "What going on" or "Whats up" usually used if you are a so called "roadman" (a person who usually goes round on a bike wearing all branded tracksuits smoking weed and drinking alcohol). A popular phrase people use with the word "Wagwan" is "Wagwan piff ting" - usually meaning "Whats going on hot (sexy) one"
Roadman: " Wagwan piff ting, hows you?"
Roadman: " W a g w a n!!!"