IPA: /ˈrɒŋˌhɛdɪdli/
KK: /ˈrɔŋˌhɛdɪdli/
In a way that shows a mistaken or misguided opinion or belief.
He wrongheadedly believed that he could solve the problem without any help.
Wrongheadedly → It is formed from "wrong" (from Old English *wrang*, meaning incorrect or unjust) and "headedly" (from "head" meaning the direction or way of thinking, combined with the adverbial suffix "-ly"). The word describes acting in a manner that is incorrect or misguided in thought or direction.
Think of someone thinking in a 'wrong' way ('wrong') and acting according to that misguided thought ('headedly'). This helps you remember that 'wrongheadedly' means acting in a misguided or incorrect manner.