Related Clues:

• Tax for work you are obliged to do
• Smiles performed it
• Anything purchased, except a book
• After introductory cancellation, did purchase have some duty?
• Expression of obligation that's repugnant in books
• Have a duty (to do)
• Old-fashioned, heartless form of tax
• Obligation; tax
• Smiles created obligation
• Have/has a duty (to do)
• to (should)
• Is advised
• Cancel (a law)
• Should duck?
• Should prove uncommonly tough