Probably akin to the base of phtheiro; ill-will (as detraction), i.e. Jealousy (spite) -- envy.

see GREEK phtheiro

φθόνοι (phthonoi) − 1 Occurrence

φθόνον (phthonon) − 4 Occurrences

φθόνος (phthonos) − 1 Occurrence

φθόνου (phthonou) − 1 Occurrence

φθόνους (phthonous) − 1 Occurrence

φθόνῳ (phthonō) − 1 Occurrence