D defs.my
Entry 1 sense Webster, 1913

Impugn

/ĭmˌ-pyo͞on'/ · Im·pugn · IPA /ɪmˈpjuːn/
01 v. t. To attack by words or arguments; to contradict; to assail; to call in question; to make insinuations against; to gainsay; to oppose; as, to…
imp. & p. p. Impugned; p. pr. & vb. n. Impugning
  1. 1.
    To attack by words or arguments; to contradict; to assail; to call in question; to make insinuations against; to gainsay; to oppose; as, to impugn a person's integrity.
    “The truth hereof I will not rashly impugn, or overboldly affirm.” — Peacham.