IPA: //ʌnˈtruːli//
KK: /ʌnˈtruːli/
In a way that is not true or accurate.
He spoke untruly about his achievements.
Untruly → It is formed from "un-" (meaning not) and "truly" (from Old English "trūwlic", meaning faithful or true). The word "untruly" means not in a true or faithful manner.
Think of 'not' ('un-') being added to 'true' — this helps you remember that 'untruly' means not true or not faithful.