low intelligence; feeble-mindedness
Refers to the state or quality of having low intellectual ability. Often used in derogatory or clinical contexts.
He has low intelligence, so he can only be entrusted with simple tasks.
It's not good to look down on people with low intelligence.
unintelligent person; imbecile
A person with low intelligence. Derogatory when used directly; can be insulting.
It's useless to say anything to such an imbecile.
知能 means 'intelligence' in a neutral sense; 低能 is the negative counterpart meaning 'low intelligence'.
feeble-minded child; slow learner; poor student
imbecile; moron; feeble-minded person
Standard kanji spelling.
Irregular kanji usage; 脳 means 'brain', giving a more directly insulting nuance. Rarely used.
Compound of 低 (てい, 'low') and 能 (のう, 'ability, talent'). The irregular form 低脳 replaces 能 with 脳 (brain), emphasizing mental deficiency.