IPA: /ʌnˈhɛlθɪli/
KK: /ʌnˈhɛlθɪli/
In a way that is not good for health or well-being.
Eating too much junk food can lead to living unhealthily.
Unhealthily → It is formed from "un-" (meaning not) and "healthy" (from Old English "halig", meaning whole or sound) and the suffix "-ly" (meaning in a manner). The word "unhealthily" means in a manner that is not healthy or detrimental to health.
Think of 'not' ('un-') being combined with 'whole' or 'sound' ('healthy') to remember that 'unhealthily' describes a way of living that is not good for your health.