Related Clues:

• Wear down
• Makeshift swing
• Change direction
• With 43-Across, leaver of a mark
• Rod in a hot rod
• One may become bald
• Weary
• It may need air
• Grow weary
• The fifth is spare
• It can wear down from too much travel
• Get jaded
• Knock out
• It's carried in a trunk
• Rotate