People lacking in common sense or a modicum of intelligence, or people with big fat heads on their shoulders.
This country{USA is full of thickheads because we elected Donnie Trump for President. A classic case of the dumbing down of America.
by Donald Cowboy Cerrone October 12, 2017
Numbskull, idiot, Bill Gates, bonehead, shmoe, Bill Gates, imbecile, Bill Gates, Bill Gates, Dubbya.
by Bastardized Bottomburp March 21, 2003
When you wakeup in the morning with an awful hangover (thickhead) but then you realize how much fun you had (grin).
Al woke up with a terrible headache after his 40th birthday party by then remembered how much fun he had. He was experiencing a thickhead grin.
by ARTIFAX January 26, 2009