Possible Clues:

• Diminish, as support
• Slowly break down
• Cause to gradually vanish
• Gradually destroy, as shoreline
• Wear down recent royal elegy?
• Riding 'e was so as to wear it away
• Wear in bad weather?
• Crumble into the sea, as shoreline
• Grind away before sealing arrangement with bank
• What to do up in the broken reed is so wearing