oppugn

Oppugn was first recorded in English in the 15th century. It came to Middle English from the Latin verb oppugnare, which in turn derived from the combination of ob-, meaning "against," and pugnare, meaning "to fight." Pugnare itself is descended from the same ancient word that gave Latin the word pugnus, meaning "fist." It's no surprise, then, that oppugn was adopted into English to refer to fighting against something or someone, either physically (as in "the dictatorship will oppugn all who oppose it") or verbally (as in "oppugn an argument"). Other descendants of pugnare in English include the equally aggressive pugnacious, impugn, repugnant, and the rare inexpugnable ("incapable of being subdued or overthrown").