Related Clues:

• Sang-froid
• Not windy
• Down-to-earth
• On one's rocker?
• Repose
• Untroubled
• Sedate
• Thoughtful
• Like the eye of a storm
• Tranquil
• Not at all excited
• Having a full set of marbles
• Yachter's woe
• Sound upstairs
• Of sound mind