Where does “half-brained” come from?

half-brained (English) comes from English brained, from English brain, from Middle English brayn, from Old English bræġn, from Proto-West Germanic *bragn, from Proto-Germanic bragną, from Proto-Indo-European mregʰnom, from Proto-Indo-European men- — to think, mind; spiritual activity; to stay,...

half-brained (English): Exhibiting low intelligence, as if having only...

Definitions

  1. Exhibiting low intelligence, as if having only...

Ancestry of “half-brained”, step by step

half-brained traces back through two separate lines of ancestry.

via English brained

StepLanguageWordMeaning
1EnglishbrainedHaving a particular kind or number of brain;...
2EnglishbrainThe control center of the central nervous system...
3Middle EnglishbraynThe brain or cerebrum; the organ of thought;...
4Old Englishbræġnbrain
5Proto-West Germanic*bragnbrain
6Proto-Germanicbragnąbrain
7Proto-Indo-Europeanmregʰnomskull, brain
8Proto-Indo-Europeanmen-to think, mind; spiritual activity; to stay,...

via English half

StepLanguageWordMeaning
1EnglishhalfConsisting of a half; Consisting of some...
2Middle Englishhalfhalf
3Old Englishhealfside; half; partly
4Proto-Germanic*halb
5Proto-Germanichalbazhalf
6Proto-Indo-European(s)kelH-to cut; to split, to separate
7Proto-Indo-European(s)kel-to bend, crook; bent, crooked; leg, heel, knee,...
Every word from Proto-Indo-European men-Every word from Proto-Indo-European mregʰnomEvery word from Proto-Germanic bragną