Etymology tree English clueless 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 cluelessness From clueless + -ness.