MAD
adjective. (madder, maddest) 1 insane; frenzied. 2 wildly foolish. 3 (often foll. By about, on) colloq. Wildly excited or infatuated. 4 colloq. Angry. 5 (of an animal) rabid. 6 wildly light-hearted. ? like mad colloq. With great energy or enthusiasm. ? madness none. [old english]