Related Clues:

• Cool, quaintly
• Old-fashioned ''Cool!''
• Old-style ''Sweet!''
• ___ Four (The Beatles)
• Like the Beatles in their heyday
• Retro "Cool!"
• Dynamite half of 19 across
• 'Suh-weet!'
• Word describing the "Four" Beatles
• "Groovy!" relative
• Adjective for a British Invasion foursome
• Old-fashioned 'Awesome!'
• "How cool!"
• 'Sick!,' once
• "That's really cool!"