IPA: //laɪtˈhɑːrtɪdli//
KK: /ˈlaɪtˌhɑːrtɪdli/
In a way that is cheerful and carefree, without serious thoughts or worries.
She lightheartedly joked about the situation, making everyone laugh.
Lightheartedly → It is formed from "light" (from Old English *leoht*, meaning not heavy or bright) and "heartedly" (from "heart" (from Old English *heorte*, meaning the organ of emotion) and the suffix "-ly" (meaning in a manner of). The word "lightheartedly" means in a manner that is cheerful and carefree, reflecting a lightness of heart.
Think of being 'not heavy' ('light') and acting in a way that reflects your 'heart' ('heartedly') — this helps you remember that lightheartedly means to act in a cheerful and carefree manner.