Related Clues:

• Get the pot going
• Gambler's obligation
• Story starter
• It's a start
• What's required to be 'in'
• Sammy Kaye's '___ Tomorrow'
• Erstwhile
• Opening bit
• Start to date
• Leading
• Grimm beginning
• See 6-Down
• See 54-Across
• Play opener
• Enough, for some