of Impugn
Source: Webster's dictionaryBefore impugning an opponent's motives, even when they legitimately may be impugned, answer his arguments. Sidney Hook
Therefore, if the low-key nature of the ceremony was meant to be publicly taken as indicative of the child's illegitimacy, he would be impugning his wife's honour, and exposing himself as a cuckolded husband into the bargain, to no good end. Source: Internet
Rumours impugning his integrity deeply troubled Falcone during this period. Source: Internet
Walker, p 229. The ACLU lost the case of Joseph Beahharnais, who was arrested for group libel when he distributed literature impugning the character of African Americans. Source: Internet