IPA: /ʌnˈhæpɪli/
KK: /ʌnˈhæpɪli/
In a way that shows sadness or lack of happiness.
She smiled, but deep down, she felt unhappily about the situation.
Unhappily → It is formed from "un-" (meaning not) and "happy" (from Old English "hap", meaning fortune or luck) and "-ly" (meaning in a manner). The word "unhappily" means in a manner that is not happy or unfortunate.
Think of 'not' ('un-') being added to 'happy' — so when someone is unhappy, they are experiencing life in a way that is not fortunate.