smooth brain

== English == === Alternative forms === smoothbrain === Etymology === 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. === Noun === smooth brain (plural smooth brains) (derogatory, offensive) A stupid person. Synonyms: see Thesaurus:fool, Thesaurus:idiot Used other than figuratively or idiomatically: see smooth,‎ brain.