smooth brain

derogatory offensive vulgar broadly

A stupid person. / (by extension) Term of abuse. / Used other than figuratively or idiomatically: see smooth, brain.

Japanese Meaning

馬鹿な人。知能が低く、判断力に欠ける人を指す侮蔑的な言い方。 / 軽蔑の意味で、愚かな行動や考えを持つ人を示す表現。

Don't be a smooth brain and ignore the instructions.

指示を無視するような頭の悪い人になるな。

Sense（1）

A stupid person.

Sense（2）

(by extension) Term of abuse.

I could not have made it easier for you smooth brains, yet you still messed up!

Sense（3）

Used other than figuratively or idiomatically: see smooth, brain.

smooth brains

（ plural ）