Definition of "reductio" [reductio]

• (reduction to the absurd) a disproof by showing that the consequences of the proposition are absurd; or a proof of a proposition by showing that its negation leads to a contradiction (noun)

WordNet. Princeton University. 2010.

• "So as to leave no doubt about my sincerity, I note that the term reductio ad absurdum was invented by dead white males to justify their oppressive patriarchal racist imperalist hegemony."
• "They love engaging in reductio ad absurdium and other fallacies to try and twist it to their point."
• "The phrase reductio ad Hitlerum was coined by an academic ethicist, Leo Strauss, in 1953."