Possible Clues:

• 'Malign, badmouth (7)'
• Speak badly of drug, taken regularly in tiny amount
• Calumniate, speak badly of
• Tell lies about (someone)
• Speak badly of
• Defame jazz function in speech
• Bad-mouth picture put up by Mussolini
• Malign deal protecting University College
• Malign — rude act (anag)
• Malign notice interrupts attempt to stop war