Related Clues:

• Way in the past
• Never before and never again
• First word in many a fairy tale
• "Going ___ ..." (auctioneer's cry)
• Not to be repeated
• In days of old
• "Going __, going ..."
• A long time past
• Start of a bedtime story
• "___ Upon a Time in America"
• 'The Raven' opening
• A good while back
• ___ a day
• It's often enough
• Second word in many limericks