IPA: /ˈʃɔːrtli/
KK: /ˈʃɔrtli/
In a short amount of time; soon.
The meeting will start shortly after lunch.
Shortly → It is formed from "short" (from Old English *sceort*, meaning brief or small in length) and "-ly" (meaning in a manner of). The word "shortly" means in a brief manner or for a short time.
Think of something being 'brief' ('short') and done 'in a manner' ('-ly') — that's why shortly means to do something in a brief way.