Possible Clues:

• Mark time when one's powers decline
• Point to mature years as cause of senility
• Weakness of mind from old age
• Girl taking a long time to show excessive fondness
• Feeble-minded period late in life
• Old age gives one time for 13 across, it seems
• Perhaps time for a full stop, but too old for anything else
• Foolish time to put identifying mark into deer
• In which one would be old and weak
• Practise children’s game with energy and fondness