Related Clues:

• Lose enthusiasm
• "Works for me!"
• ''That's great!''
• In the 50s or 60s, say
• 'Very nice!'
• On an even keel
• Warmer than chilly
• Calm under pressure
• Hard to rattle
• Even-tempered
• Calm, ___ and collected
• Slangy-but-enduring term of approval
• Less than chilly
• "Sounds great"
• Partner of calm and collected