IPA: /ɡroʊˈtɛskli/
KK: /groʊˈtɛskli/
In a way that is very strange or unnatural, often causing disgust or shock.
The painting was grotesquely distorted, making the figures look monstrous.
Grotesquely → It is formed from "grotesque" (from Italian *grottesco*, meaning of a cave or cavern) and the suffix "-ly" (meaning in a manner). The word "grotesquely" means in a manner that is bizarre or unnatural, often in a way that is comically or absurdly exaggerated.
Think of something that is 'of a cave' ('grotesque') and how it can appear in a strange or exaggerated way — that's why 'grotesquely' means in a bizarre manner.