Possible Clues:

• Any aromatic univalent hydrocarbon radical
• Of a certain hydrocarbon group
• Chemical group derived from benzene
• Benzene derivative, for one
• Aromatic univalent hydrocarbon radical
• Aromatic hydrocarbon derivative
• Some revolutionary lefties in compound
• Radical contributing to customary lawlessness
• Radical investment of railway in a line
• Radical involved in revolutionary liberation