Possible Clues:

• Meal not started before being cancelled - that's a blow
• Reason for pain in jaw that's reduced by drug
• Boxer's tactic
• Wide awake for each score will knock you out
• Blow up and erupt, possibly enveloping country's capital
• Part of the shoe damaged? Blow!
• Boxing punch delivered vertically
• Knockout punch, at times
• Reduce support for part of Oxford, perhaps -- that's a blow
• Chuck steak, for example?