dispute or contradict (often in an insulting way); challenge; gainsay
How dare you impugn my expertise when you know that I even have a PhD in this subject?
in (into, in, on, upon)#pugnus (fist) (Latin)
censure, decry, denounce, deplore, deprecate, impugn, lambaste, reproach, upbraid
extol, laud, lionize
We know PUGNACITY as "PUNGA CITY" pugn means "attack". and impugn means to attack with words or arguments. ! im + PUGN ~ pugn looks like pungaa (hindi); NOW think of a person who is habitual of taking PUNGAA, he will always CONTRADICT people, and will always CHALLENGE others (impugn others). pugn is root word meaning fight. (for eg. pugnacious means quarrelsome) so impugn means sense of contradicting in order to cause a dispute