from
The Collaborative International Dictionary of English v.0.48
Impugn \Im*pugn"\, v. t. [imp. & p. p. {Impugned}; p. pr. & vb.
n. {Impugning}.] [OE. impugnen, F. impugner, fr. L.
impugnare; in on, against + pugnare to flight. See
{Pugnacious}.]
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.
[1913 Webster]
The truth hereof I will not rashly impugn, or
overboldly affirm. --Peacham.
[1913 Webster]