1. most peaceful, quiet, or free from disturbance (superlative form of calm)
2. most relaxed and not showing worry, anger, or excitement (superlative form of calm)

Examples

• She remained the calmest person in the room during the emergency.
• The lake was at its calmest just before dawn.
• He spoke in his calmest voice to avoid escalating the argument.
• This is the calmest I’ve ever seen the ocean.
• Even under pressure, she was the calmest member of the team.
• The calmest days of summer are perfect for sailing.
• His calmest moments come when he’s reading by the fireplace.