Definitions:

1. Acting with a lack of warmth, enthusiasm, or emotional involvement. ADVERB
   • He coolly dismissed the idea without much thought.
2. Handling a situation with ease and confidence, often implying a lack of concern. ADVERB
   • The player coolly took the penalty shot and scored the winning goal.
3. Performing an action with self-control and without showing nervousness or agitation. ADVERB
   • She coolly responded to the accusation, showing no sign of distress.

Synonyms:

• calmly
• collectedly
• composedly
• dispassionately
• indifferently
• nonchalantly