FarsiPronunciation: /ˈfɑːsiː/Definition of Farsi noun [mass noun] the modern Persian language, the official language of Iran, with over 20 million speakers: [as modifier]:a Farsi expressionOrigin:from Arabic fārsī, from Fārs, from Persian Pārs 'Persia'. Compare with ParseeFarsi in other Oxford dictionaries Definition of Farsi in the US English dictionary