The Collaborative International Dictionary of English v.0.48:
Overpowering \O`ver*pow"er*ing\, a. Excelling in power; too powerful; irresistible. -- O`ver*pow"er*ing*ly, adv. [1913 Webster]WordNet (r) 3.0 (2006):
overpoweringly adv 1: incapable of being resisted; "the candy looked overwhelmingly desirable to the dieting man" [syn: overwhelmingly, overpoweringly, irresistibly]