catechin UK /ˈkatɪt͡ʃɪn/US /ˈkæt.ə.t͡ʃɪn/ noun1 •A flavanol derived from catechol (2R,3S)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-chromene-3,5,7-triol formscatechins