impugn
/ɪmˈpjuːn/
verb
- To attack or criticize someone's character, motives, or reputation; to challenge the truth or validity of something.
- The article impugns the safety of the new drug without providing solid evidence.
- The lawyer tried to impugn the witness's credibility by pointing out past lies.
- No one dared to impugn the CEO's integrity after years of honest leadership.