IPA: /ˈkuːli/
KK: /ˈkuːli/
In a calm and composed way, without showing strong emotions or excitement.
She handled the unexpected news coolly, maintaining her composure throughout the meeting.
Coolly → It is formed from "cool" (from Old English *cōl*, meaning moderately cold or lacking warmth) and the suffix "-ly" (meaning in a manner of). The word "coolly" means in a manner that is calm, composed, or lacking warmth of emotion.
Think of being "calm" or "moderately cold" when you act "coolly" — the suffix "-ly" just means in that manner.