Related Clues:

• Wear down
• Makeshift swing
• With 43-Across, leaver of a mark
• One may become bald
• Weary
• It may need air
• Grow weary
• The fifth is spare
• It can wear down from too much travel
• Steinway lever
• Get jaded
• Knock out
• It's carried in a trunk
• Start to give out
• Run out of gas