IPA: //ˈbruːtəli//
KK: /brutəli/
In a way that is rough, violent, or lacking in kindness.
He spoke brutally to his opponent during the debate.
Brutely is formed from "brut" (from Old French *brut*, meaning rough or savage) and the suffix "-ly" (meaning in a manner of). The word "brutely" describes an action done in a rough or savage manner.
Think of the word 'brut' which means rough or savage, and remember that 'brutely' means doing something in a rough or savage way.