to challenge as false (another's statements, motives, etc.); cast doubt upon.

Archaic . to assail (a person) by words or arguments; vilify.

Obsolete . to attack (a person) physically.

verb

flatter , praise

verb

assail , attack , blast , break , call into question , cast aspersions upon , cast doubt upon , come down on * , contradict , contravene , cross , cut to shreds , deny , disaffirm , dispute , gainsay , knock * , negate , negative , oppose , pin something on , put down * , question , resist , run down , skin alive , slam * , smear * , stick it to , swipe at , tar * , throw doubt on , throw the book at , thumb nose at , traduce , trash , traverse , zap * , zing *notes:to impugn is to dispute the truth , validity , or honesty of; to oppugn is to dispute the truth or validity of , to strive against , attach , denounce , doubt , knock