feebleminded

Adjective

feeble-minded (comparative more feeble-minded or feebler-minded, superlative most feeble-minded or feeblest-minded)

1. Weak in intellectual power; lacking firmness or constancy; lacking intelligence.
   • Wading through history, he noted that some eugenicists believed that the “distinction between the fit and the unfit could be drawn along racial lines,” and others would define a person as “feeble-minded.”2019 May 28, Ariane de Vogue, “Why Clarence Thomas wrote over a dozen pages on eugenics”, in CNN

   Synonyms:

   irresolute, vacillating, imbecile