Related Clues:

• Nifty, in the 50's
• 'Good going!'
• 'Uh-huh'
• 'You bet!'
• First-rate
• Hunky-dory
• Peachy-keen
• Spiffy
• 'Far out!'
• Marvy
• Fine, informally
• 'Cool!'
• Cool
• Oater affirmative
• 'Why not?'