feeble-mindedness

Etymology tree
Anglo-Norman feblebor.
Middle English feble
English feeble
English mind
English -ed
English minded
English feeble-minded
Proto-Germanic *-inōną
Proto-Indo-European *-dyé-
Proto-Germanic *-atjaną
Proto-Indo-European *-tus
Proto-Germanic *-þuz
Proto-Germanic *-assuz
Proto-Germanic *-inassuz
Proto-West Germanic *-nassī
Old English -nes
Middle English -nesse
English -ness
English feeble-mindedness
From feeble-minded + -ness.