Related Clues:

• Gnarly
• "Groovy!"
• 'Gnarly!'
• "Gnarly!"
• X-ray unit
• Far out!
• More than cool
• 90's kids' catchword
• Sterling
• Exquisite
• 'Cool'
• Unit of 100 ergs per gram
• 'Out of sight!'
• Good, at the beach
• "Far out!" to a physicist?