IPA: /juːˈfoʊniəsli/
KK: /juˈfoʊniəsli/
In a way that sounds pleasant and harmonious to the ear.
The choir sang euphoniously, filling the hall with beautiful melodies.
Euphoniously → It is formed from "eu-" (meaning good or well) and "phone" (from Greek "phōnē", meaning voice or sound) and the suffix "-ous" (meaning full of) and "-ly" (meaning in a manner). The word "euphoniously" means in a manner that is full of good sound or pleasant to hear.
Think of 'good' ('eu-') sounds ('phone') to remember that 'euphoniously' means something is pleasing to hear.