Meaning

noun poor physical condition; being out of shape or out of condition (as from a life of ease and luxury)

noun lacking the power to perform

noun the quality of not being suitable

originEtymology tree English unfit 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 unfitness From unfit + -ness.

Etymology from Wiktionary, CC BY-SA 3.0