Possible Clues:

• Biscuit, for a dog
• Buy a drink for, for instance
• Pay for everyone's meal
• Deal with entertainment paid for by another
• Milk-Bone biscuit, e.g.
• Chocolate bonbon, e.g.
• Deal with rubbish round about
• One part of a Halloween question (Note: Enter the alphabetically first answer to "complete" the puzzle!)
• Dog-training aid
• Pay for someone's food or entertainment