thickhead

noun

1. a stupid person; blockhead.
2. Also called whistler. any of several Old World birds of the genus Pachycephala, chiefly of various islands in the Pacific Ocean, related to the flycatchers, and having a melodious whistling call.

noun

1. a stupid or ignorant person; fool
2. Also called: whistler any of various Australian and SE Asian songbirds of the family Muscicapidae (flycatchers, etc)