The Collaborative International Dictionary of English v.0.48:
mack \mack\ n. A mackintosh; -- a shortened form. Syn: macintosh, mackintosh, mac. [WordNet 1.5]WordNet (r) 3.0 (2006):
mack n 1: a waterproof raincoat made of rubberized fabric [syn: macintosh, mackintosh, mac, mack]