radical

adjective
rad·​i·​cal | \ˈra-di-kəl \

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

radical

noun

Definition of radical (Entry 2 of 2)

1a : a root part

b : a basic principle : foundation

2a : root sense 6

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

b : radical sign

Keep scrolling for more

Other Words from radical

Adjective

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 White House Twitter account represents another radical shift in the Trump administration that changes the course of conduct in the national dialogue. Julyssa Lopez, Glamour, "The Official White House Twitter Account Just Went After Two Women Senators," 3 July 2018 Everything from multi-camera broadcasting options to helmet cams to in-game gambling are among the more radical ideas under consideration. Mitchell Gladstone, Philly.com, "Soul owner Ron Jaworski believes the Arena Football League, down to just four teams, will rise again," 15 June 2018 That was another radical idea for D’Antoni, the NBA’s most imaginative offensive mind whose teams have often been allergic to defense, and yet look where the Rockets are now. Ben Cohen, WSJ, "The Rockets Are Beating the Warriors With Defense. Really.," 25 May 2018 The policy itself wasn’t a radical departure from Trump’s long-running antipathy toward Muslims. Matt Ford, The New Republic, "Should Trump’s Bigotry Disqualify His Travel Ban?," 25 Apr. 2018 Among the artists who transformed painting in the 20th century, Henri Matisse and Pablo Picasso come to mind first, but their contemporary, the French artist Pierre Bonnard (1867-1947), was also something of a radical. Sidney Lawrence, WSJ, "A Muse Embedded in Mystery," 22 June 2018 Putin grew increasingly enamored of reactionary social theories portraying traditional, conservative, Christian Europe as pitted in a civilizational struggle against both decadent liberalism and radical Islam. Jonathan Chait, Daily Intelligencer, "Will Trump Be Meeting With His Counterpart — Or His Handler?," 8 July 2018 In 2016, a few months before a political tidal wave hit America, Minot took a radical step of its own. The Economist, "How a small town in North Dakota got its groove back," 7 June 2018 Getting rid of the people that perpetuate radical diets and fitness programs within the organization (because there are DEFINITELY some of those) should have been the first step. Cady Drell, Marie Claire, "The Case For Miss America's Swimsuit Competition," 6 June 2018

Recent Examples on the Web: Noun

Cultural radicals from the era like Alice Schwarzer, a feminist commentator, are now part of the talk-show establishment. The Economist, "The legacy of Germany’s student protests in 1968," 31 May 2018 The suspect, who is married to a German woman, allegedly was in contact with Islamic radicals and twice tried to travel to Syria last year, investigators said. Frank Jordans, chicagotribune.com, "Tip from public helped Germany foil ricin attack plot," 20 June 2018 Tariq Ali edited the Black Dwarf and then the Red Mole (Marxist papers which—perhaps oddly, given their influence with British radicals of the era—are not discussed in much detail). The Economist, "1968 was no mere year," 5 Apr. 2018 Saudi rulers were handling the hardware, while radicals rewrote the nation’s software. Adel Al-toraifi, WSJ, "The Saudis Take On Radical Islam," 19 Mar. 2018 Among them were Democrats and Republicans, radicals and conservatives, rabble rousers and club women, the flamboyant and the staid. Fergus M. Bordewich, WSJ, "‘The Woman’s Hour’ Review: Friends and Foes of the 19th Amendment," 21 June 2018 The waifs and radicals may be gone, but the atmosphere in the Flore and beyond is more highbrow than the doomsayers imply. The Economist, "The death—or reinvention—of the French intellectual," 28 Apr. 2018 And who are these wild-eyed radicals and socialists? Will Bunch, Philly.com, "Why they risked everything to Occupy ICE | Will Bunch," 5 July 2018 Fraser’s main explanation is Cold War anti-communism, which gave conservatives the chance to press radicals to the margins or persecute them outright. Jedediah Purdy, The New Republic, "The Remaking of Class," 27 June 2018

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.

See More

First Known Use of radical

Adjective

14th century, in the meaning defined at sense 1

Noun

1641, in the meaning defined at sense 1a

History and Etymology for radical

Adjective

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

Keep scrolling for more

Learn More about radical

Statistics for radical

Last Updated

11 Nov 2018

Look-up Popularity

Time Traveler for radical

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

See more words from the same century

Keep scrolling for more

More Definitions for radical

radical

adjective

English Language Learners Definition of radical

 (Entry 1 of 2)

: very new and different from what is traditional or ordinary

: very basic and important

: having extreme political or social views that are not shared by most people

radical

noun

English Language Learners Definition of radical (Entry 2 of 2)

: a person who favors extreme changes in government : a person who has radical political opinions

radical

adjective
rad·​i·​cal | \ˈra-di-kəl \

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

radical

noun

Kids Definition of radical (Entry 2 of 2)

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

radical

adjective
rad·​i·​cal | \ˈrad-i-kəl \

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 \ adverb

radical

noun

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

Keep scrolling for more

Comments on radical

What made you want to look up radical? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

obstinately defiant of authority

Get Word of the Day daily email!

Test Your Vocabulary

Autumn Words of the Day 2018

  • a-top-down-image-of-road-through-an-autumn-forest
  • Which is a synonym of fugacious?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!