2. (noun)loon, diver large somewhat primitive fish-eating diving bird of the northern hemisphere having webbed feet placed far back; related to the grebes Synonyms: addlehead, diver, plunger, addle-head, underwater diver, frogman, loon, birdbrain
3. (noun)addle-head, addlehead, loon, birdbrain a person with confused ideas; incapable of serious thought Synonyms: diver, loon, addlehead, addle-head, birdbrain
Synonyms and Antonyms of loon 
