The Collaborative International Dictionary of English v.0.48:
crawdad \craw"dad\ (kr[add]"d[a^]d), crawdaddy \craw"dad*dy\(kr[add]"d[a^]d*d[y^]), n. (Zool.) same as crawfish [PJC] CrawfishWordNet (r) 3.0 (2006):
crawdaddy n 1: small freshwater decapod crustacean that resembles a lobster [syn: crayfish, crawfish, crawdad, crawdaddy]