Who doesn't love a good game of mad libs? Supply the Word is basically the same idea. 2-3 actors will begin a scene. At various points in the scene, each of the actors will stick out their hand to the audience. This means they want the audience to give the next word they will say. Once they have one, they will say the word provided, and justify it in the scene. It's like organized chaos.
WARNING: Some scenes may contain explicit language and mature subject matter. Viewer discretion is advised.