IPA: //ʌnˈtruːər//
KK: /ʌnˈtruːər/
Not true; false or incorrect.
His statement was even untruer than I had thought.
Comparative: more untrue
Superlative: most untrue
Untruer → It is formed from the prefix "un-" (meaning not) and the root "true" (from Old English "triewe", meaning faithful or loyal) and the suffix "-er" (meaning one who). The word "untruer" means one who is not true or faithful.
Think of 'not' ('un-') and 'faithful' ('true') to remember that 'untruer' refers to someone who is not faithful.