smooth brain
nounEtymology Nominalization of smooth-brained, possibly by reference to lissencephaly (a brain abnormality, usually resulting in severe developmental delay, characterized by the surface of the brain being smooth), or simply by reference to the human brain typically being wrinkly.
1
Derogatory, Offensive A stupid person.
- I could not have made it easier for you smooth brains, yet you still messed up!
2
Derogatory, Offensive Used other than figuratively or idiomatically: see smooth, brain.