Related Clues:

• "That's really cool!"
• Groovy relative
• Swell kin
• "___ Four" (The Beatles)
• Quaint 'cool'
• Marvelous, slangily
• "That's really spiffy!"
• 'That's really spiffy!'
• Terrific, in the Beatles Era
• 'Coo-oo-ool!'
• Beatles nickname word
• __ Four
• Cool kin
• 'Coolio, daddy-o!'
• 'Pretty slick!'