rad·​i·​cal | \ ˈra-di-kəl How to pronounce radical (audio) \

Definition of radical

 (Entry 1 of 2)

1 : of, relating to, or proceeding from a root: such as
a(1) : of or growing from the root of a plant radical tubers
(2) : growing from the base of a stem, from a rootlike stem, or from a stem that does not rise above the ground radical leaves
b : of, relating to, or constituting a linguistic root
c : of or relating to a mathematical root
d : designed to remove the root of a disease or all diseased and potentially diseased tissue radical surgery radical mastectomy
2 : of or relating to the origin : fundamental
3a : very different from the usual or traditional : extreme
b : favoring extreme changes in existing views, habits, conditions, or institutions
c : associated with political views, practices, and policies of extreme change
d : advocating extreme measures to retain or restore a political state of affairs the radical right
4 slang : excellent, cool



Definition of radical (Entry 2 of 2)

1a : a root part
b : a basic principle : foundation
b : a sound or letter belonging to a radical
3 : one who is radical
4 : free radical also : a group of atoms bonded together that is considered an entity in various kinds of reactions or as a subunit of a larger molecule
5a : a mathematical expression indicating a root by means of a radical sign

Other Words from radical


radicalness noun

Examples of radical in a Sentence

Adjective The computer has introduced radical innovations. There are some radical differences between the two proposals. The new president has made some radical changes to the company. a radical wing of extremists Noun He was a radical when he was young, but now he's much more moderate. radicals staged large, violent protests in the hopes of toppling the government See More
Recent Examples on the Web: Adjective The transactions represent a radical change of fortune for senior princes who funneled windfalls from oil booms in the 1970s and 1980s into some of the world’s most exclusive markets. Stephen Kalin, WSJ, 24 Apr. 2022 In truth, such a change would've been a radical, revolutionary departure from America's electoral traditions. Joel Mathis, The Week, 15 Apr. 2022 After a meteoric career as a model, living in major cities in the United States and Europe, the pandemic provoked a turning point for a radical change in her life and interests. Vogue, 7 Apr. 2022 The second involves more radical change: All companies would have to adopt and implement one universal encryption standard. Matt Burgess, Wired, 29 Mar. 2022 But her desire for more radical change had led her to the Tea Party, and increasingly to the party’s fringes. New York Times, 26 Mar. 2022 The prominence of such a conversation is itself a radical departure from how questions had been dealt with in the past. Simone Mccarthy, CNN, 25 Mar. 2022 Mooney also hired a chief digital products officer, a radical departure for a company which for three quarters of a century mainly made products of wood and metal. Matt Schifrin, Forbes, 18 Mar. 2022 As the pandemic continues, the lack of domestic help requires a radical change in behavior. James Max, Harper’s Magazine , 16 Mar. 2022 Recent Examples on the Web: Noun Opa chafed in particular at the books and articles that reinforced the Nazi claim that Arthur had been a political radical. Mattie Kahn, The Atlantic, 5 May 2022 The Left is busy convincing itself that Youngkin has morphed into a radical. The Editors, National Review, 19 Jan. 2022 However, critics have painted her as a dangerous radical, recalling Zelaya's closeness to late Venezuelan president Hugo Chavez. Reuters, CNN, 29 Nov. 2021 Thus, according to Biden, Sen. Mitt Romney is alternately an honorable man who will never break his word, or a dangerous radical who will put a predominantly African-American audience back in chains. W. James Antle Iii, The Week, 23 July 2021 One explanation for her success is Ms. Wu herself, who is difficult to caricature as a radical. Ellen Barry, New York Times, 3 Nov. 2021 Miles took pains to counter the notion of McCartney as a soapy balladeer and, by inference, of Lennon as the group’s sole intellectual and artistic radical. David Remnick, The New Yorker, 11 Oct. 2021 Her college-age daughter Olivia, played by Sydney Sweeney, is a left-wing radical in Golden Goose sneakers and vintage tees, while her best frenemy Paula, played by Brittany O’Grady, lives in slogan T-shirts and a dark, brooding palette. Steff Yotka, Vogue, 16 Aug. 2021 Over dinner one night in the mid-nineties, Merkel asked Schlöndorff, a former radical, to explain the violence perpetrated by the Baader-Meinhof Group. Margaret Talbot, The New Yorker, 11 Aug. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radical.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of radical


14th century, in the meaning defined at sense 1


1641, in the meaning defined at sense 1a

History and Etymology for radical


Middle English, from Late Latin radicalis, from Latin radic-, radix root — more at root

Learn More About radical

Time Traveler for radical

Time Traveler

The first known use of radical was in the 14th century

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Dictionary Entries Near radical



radical axis

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Statistics for radical

Last Updated

19 May 2022

Cite this Entry

“Radical.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radical. Accessed 24 May. 2022.

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More Definitions for radical


rad·​i·​cal | \ ˈra-di-kəl How to pronounce radical (audio) \

Kids Definition of radical

 (Entry 1 of 2)

1 : very new and different from the usual or ordinary : extreme a radical change
2 : of or relating to people who favor rapid and sweeping changes in laws and government

Other Words from radical

radically adverb



Kids Definition of radical (Entry 2 of 2)

: a person who favors rapid and sweeping changes especially in laws and government


rad·​i·​cal | \ ˈrad-i-kəl How to pronounce radical (audio) \

Medical Definition of radical

 (Entry 1 of 2)

1 : designed to remove the root of a disease or all diseased tissue radical surgery
2 : involving complete removal of an organ radical prostatectomy — compare conservative

Other Words from radical

radically \ -​i-​k(ə-​)lē How to pronounce radical (audio) \ adverb



Medical Definition of radical (Entry 2 of 2)

: free radical also : a group of atoms bonded together that is considered an entity in various kinds of reactions

More from Merriam-Webster on radical

Nglish: Translation of radical for Spanish Speakers

Britannica English: Translation of radical for Arabic Speakers

Britannica.com: Encyclopedia article about radical


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