Related Clues:

• X-ray unit
• Far out!
• More than cool
• 90's kids' catchword
• 'Cool'
• Unit of 100 ergs per gram
• 'Out of sight!'
• Good, at the beach
• "Far out!" to a physicist?
• 'Totally tubular!'
• Like jazz musicians
• Like cool cats
• Up on the latest trends
• With it, '40s-style
• “Far out!”