between the/(one's) ears(redirected from between their ears)
between the/(one's) ears
In the head where the brain is (or should be). Often used in the phrase "have nothing between the/(one's) ears" to suggest that one does not have much common sense or basic intelligence. She seems nice enough, but I get the sense that she has nothing between her ears. Jake always goes out with really attractive guys that have nothing between the ears.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
between your earsor
between the earsINFORMAL
If someone has nothing or little between their ears or between the ears, they are not clever. Footballers often have a reputation of not having much between the ears. He doesn't have a lot between the ears. Note: These expressions are usually used light-heartedly.
Collins COBUILD Idioms Dictionary, 3rd ed. © HarperCollins Publishers 2012