Related Clues:

• Hardly the life of the party
• Blue ---, from "Yellow Submarine"
• Tiresome one
• It may be hard to swallow
• It's taken in for treatment
• Cruel one
• Sadistic sort
• Drug unit
• Tiresome sort
• Tab
• Dosage, maybe
• Grumpy person
• Annoyer
• Dose unit
• Vitamin unit