IPA: /ˈprɒmptli/
KK: /ˈprɑmptli/
In a quick and timely manner; without delay.
She responded promptly to the email.
Promptly → It is formed from "prompt" (from Latin *promptus*, meaning ready or prepared) and "-ly" (a suffix used to form adverbs). The word "promptly" means in a ready or prepared manner, or without delay.
Think of being 'ready' ('prompt') to do something 'quickly' — that's why promptly means to do something without delay.