Related Clues:

• 'Bravo!'
• 'Holy moly!'
• Nifty, in the 50's
• See 27-Across
• Superb
• Surprised cry
• Slangy approval
• Wicked
• Def, to a slangster
• It's equal to 100 ergs per gram
• Fabulous
• Peachy-keen
• Spiffy
• 'Far out!'
• Marvy