Definitions for oppugnəˈpyun
Random House Webster's College Dictionary
to assail, esp. by criticism.
to call in question; dispute.
Origin of oppugn:
1400–50; late ME < L oppugnāre to oppose, attack
question, oppugn, call into question(verb)
challenge the accuracy, probity, or propriety of
"We must question your judgment in this matter"
To contradict or controvert; to oppose; to challenge or question the truth or validity of a given statement.