<p><strong>Noun (plural, especially collectively):</strong></p><ul><li>crayfish (also referred to as crawdad, crawdaddy)<ul><li>any freshwater decapod crustacean of the genera Astacus and Cambarus, closely related to but smaller than the lobsters</li><li>any of several similar marine crustaceans, especially the spiny lobster</li></ul></li></ul>