Noun
halfwit (plural halfwits)
(informal) Someone lacking in intelligence.
It is a sore point, because you do have advantages if you have access to more than one language. You also have problems, because on bad days you don't trust yourself, either in your first or your second language, and so you feel like a complete halfwit. W. G. Sebald
The halfwit spoke, and the brainless believed. Persian Proverb