Related Clues:

• Fall from usual standard
• Temporary drop in standard
• Loss (in concentration, say?)
• Fall from the faith
• Sepal (anag)
• Expire, as an insurance policy
• Senior moment, e.g
• Subscription slip
• Mental failure
• Slip of memory
• Break in concentration
• Fail in duty
• Brain freeze
• Mental error
• Slip of the mind