Possible Clues:

• Like ancient canyon cliffs
• Wore, when the weather was inclement
• Like gullies
• Worn away by water or time
• Worn if one were riding into it
• So wearing to have ridden inside
• One was riding inside to be worn
• Worn away by weather or water
• What's worn when one was on a horse with the editor around
• Not worn the way 2 down makes one