Related Clues:

• Go from rock to dust
• Destroy bit by bit
• Take the edge off?
• Succumb to wind and water
• Slowly wear away, as a cliff face
• Under-mine
• Vanish over time
• Decrease, as support
• Eat away at the bank?
• Wear in bad weather?
• Develop ruts, say
• Destroy steadily
• Slowly disappear
• Gradually destroy
• Deteriorate slowly