IPA: /ɪmˈpjuːnər/
KK: /ɪmˈpjuːnər/
A person who challenges or questions something, especially in a critical way.
The impugner raised several valid points during the debate.
Impugner is formed from "in-" (meaning not) and "pugnare" (meaning to fight). The word describes someone who fights against or challenges something, particularly in a critical or accusatory manner.
Think of someone who is 'not' ('in-') afraid to 'fight' ('pugnare') against an idea or argument — that's why an impugner is someone who challenges or disputes.