Contraction of the greeting "What's up?" which is a contraction of "What is up?" If you're really pressed for time, greet someone with a "[sup]"?. In any case, the greeter is rhetorically asking you what is going on in your life. Roughly synonymous with hello but less hip.\n> Hipster1: Wussup?\n> Hipster2: [Nuttin]'.\n> Hipster1: [Word].\n> Hipster2: [Word is bond].\n