radicalism

American  

[rad-i-kuh-liz-uhm] / ˈræd ɪ kəˌlɪz əm /

noun

1. extreme views or practices, or the tendency to favor them, as in politics or religion; extremism.

   In the long term, the peace we seek will only be achieved by eliminating the conditions that feed radicalism and ideologies of violence.

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radicalism British  

/ ˈrædɪkəˌlɪzəm /

noun

1. the principles, desires, or practices of political radicals

2. a radical movement, esp in politics

3. the state or nature of being radical, esp in politics

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Other Word Forms

• antiradicalism
  noun
• radicalistic
  adjective
• radicalistically
  adverb

Etymology

Origin of radicalism

First recorded in 1810–20; radical + -ism

Explanation

In political science, the term radicalism is the belief that society needs to be changed, and that these changes are only possible through revolutionary means. Most people think of left-wing politics when they use the noun radicalism, although people on both ends of the spectrum can be described as radical. The word radicalism comes from the Latin radicalis, "of or having roots," which in turn arose from radix, or "root." Both radical and radicalism came out of the idea that political change must "come from the root," or the very basic source of society.

Example Sentences

Mr. Wood is a professor emeritus of history at Brown University and author of “The Radicalism of the American Revolution.”

From The Wall Street Journal • Nov. 21, 2025

“Hatred and Radicalism have no place in the USA.”

From Salon • May 22, 2025

"These horrible D.C. killings, based obviously on antisemitism, must end, NOW! Hatred and Radicalism have no place in the USA," he wrote on the Truth Social platform.

From BBC • May 22, 2025

That same year, Mr. Colaianni wrote “The Catholic Left: The Crisis of Radicalism in the Church,” an antiwar manifesto that advocated racial and social justice.

From New York Times • Oct. 13, 2016

Radicalism, as has already been shown, springs from discontent.

From The Radicalism of Shelley and Its Sources by MacDonald, Daniel J.