Related Clues:

• 'Nifty!'
• 'What a surprise!'
• Terrific
• 'Cool, man!'
• "Cool!" old-style
• ''Far out!''
• Extraordinary
• "Yikes!"
• 'Amazing!'
• 'Way cool!'
• ''Peachy!''
• 'Excellent!'
• ''Keen!''
• Far out
• Daunting