Possible Clues:

• Deteriorate ... as sledders do?
• Take a turn for the worse
• Slip away when sink fell?
• Decline energy drink, husband having complaint
• Degenerate Duke's command after first part of march?
• Try to rise twice, and fall
• Lose potential energy and deteriorate
• Idol to have trouble containing horse in decline
• Decline
• Do not rise with the sound of dissent