fla·vo·noid I. \ˈflāvəˌnȯid, ˈflav-\adjective Etymology:flavone + -oid : of, relating to, or like flavone or isoflavone in chemical structure II. noun (-s) : a flavonoid compound (as a plant pigment) — see bioflavonoid; compare anthocyanidin, anthoxanthin, chalcone