crawdad

from WordNet (r) 3.0 (2006)

crawdad
    n 1: tiny lobster-like crustaceans usually boiled briefly [syn:
         {crayfish}, {crawfish}, {crawdad}, {ecrevisse}]
    2: small freshwater decapod crustacean that resembles a lobster
       [syn: {crayfish}, {crawfish}, {crawdad}, {crawdaddy}]

from 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] Crawfish