Possible Clues:

• Become still or stale through inactivity
• Become still and stale
• It's still able to go to the bad
• Become inactive
• Become inactive (and malodorous)
• From out East fly in, but do nothing constructive
• Become still and stale, pond or people (8)
• Might one buck get fed around the North and still go to the bad
• Become foul, like bilge water
• Say the nag running in it should give up running