IPA: /ˈstʌbərnli/
KK: /ˈstʌbərnli/
In a way that shows determination not to change one's mind or attitude, even when faced with difficulties or persuasion.
She stubbornly refused to change her plans, despite the bad weather.
Stubbornly → It is formed from "stubborn" (from Old French *estoborn*, meaning unyielding or obstinate) and the suffix "-ly" (meaning in a manner of). The word "stubbornly" means in a manner that is unyielding or obstinate.
Think of someone being unyielding or obstinate ('stubborn') and the '-ly' just means in that manner. So, stubbornly means acting in an unyielding way.