acriflavine Syllabification: (ac·ri·fla·vine)Pronunciation: /ˌakrəˈflāvēn/Definition of acriflavine noun a bright orange-red dye derived from acridine, used as an antiseptic. Origin: early 20th century: formed irregularly from acridine and flavineacriflavine in other Oxford dictionaries Definition of acriflavine in the British & World English dictionary