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

These prisons and camps "are hotbeds of radicalism", said Laurence Bindner, a specialist of radicalisation online.

From Barron's • Jan. 21, 2026

He was a political progressive who abhorred radicalism, an antimonopolist who recognized the inevitability of large corporations and chose to regulate rather than ban them.

From The Wall Street Journal • Dec. 29, 2025

Tracy’s script, a faithful yet singular remake of the 2003 South Korean film, “Save the Green Planet!,” shrewdly analyzes how quickly contemporary hopelessness breeds radicalism.

From Salon • Oct. 31, 2025

US President Donald Trump also decried antisemitism in response to the attack, writing on his social media platform Truth Social that "hatred and radicalism have no place in the USA."

From BBC • May 22, 2025

She liked Diana, really she did, yet she found herself avoiding her friend as though radicalism were something catching, like diptheria.

From "Lyddie" by Katherine Paterson