phenylenediaminePronunciation: /ˌfɛnɪliːnˌdʌɪˈeɪmiːn, -dʌɪˈam-, ˈdʌɪəmiːn/Definition of phenylenediamine noun [mass noun] Chemistry a synthetic crystalline compound used widely in the manufacture of dyes and other chemicals and as a photographic developer. Chemical formula: C6H4(NH2)2: three isomers
