Latin infirmitas

← Proto-Indo-European *dʰer- (root)

← Proto-Indo-European *dʰer- (derived)

← Proto-Italic *fermos (inherited)

← Latin īnfirmus (affix)

← Latin -itās (affix)

← Latin in- (affix)

← Latin firmus (affix)

→ Spanish enfermedad (derived)

→ Middle French infirmité (borrowed)