Related Clues:

• Show signs of weakening
• Gnaw at
• Eat away at the beach?
• Lose ground, literally
• Destroy slowly
• Steadily reduce, in a way
• Disappear slowly, in a way
• Deteriorate, in a way
• Make bank withdrawals?
• Partly eat away
• Slowly reduce, as a cliff face
• Slip away, as support
• Gradually diminish
• Diminish slowly
• Become smaller