radical

1 of 2

adjective

rad·​i·​cal ˈra-di-kəl How to pronounce radical (audio)
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
3
a
: 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
radicalness noun

radical

2 of 2

noun

1
a
: a root part
b
: a basic principle : foundation
2
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
5
a
: a mathematical expression indicating a root by means of a radical sign

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
Recent Examples on the Web
Adjective
The radical optimism of fans hoping for a new Dua Lipa album has finally paid off. Hannah Dailey, Billboard, 13 Mar. 2024 But some leaders are already renewing calls for a more radical overhaul. Libor Jany, Los Angeles Times, 13 Mar. 2024 The overall effect is radical, something that really changes the game for this large sedan. Tim Stevens, Robb Report, 13 Mar. 2024 Where to watch Black Sunday: Tubi 21 of 30 Eyes Without a Face (1960) Released the same year as Black Sunday, this horror outing from French director Georges Franju combines skilled artistry and grotesque gore in a way that’s even more radical than Bava’s film. Katie Rife, EW.com, 12 Mar. 2024 The events start with another radical African leader, Gamal Abdel Nasser of Egypt, and his takeover of the Suez Canal in 1956 and continues well after Lumumba’s murder to show how the world changed after him. Murtada Elfadl, Variety, 11 Mar. 2024 Biden’s radical green agenda than protecting Kentuckians’ health or the environment, said Kentucky Attorney General Russell Coleman, who is leading the joint lawsuit along with West Virginia Attorney General Patrick Morrisey. Matthew Daly, Quartz, 6 Mar. 2024 In nonfiction, two memoirs take on ideas of manhood, while journalists consider revolution and radical caregiving. Bethanne Patrick, Los Angeles Times, 1 Mar. 2024 Ford said the Super Van’s radical bodywork could generate 4,400 pounds of aerodynamic downforce at 150 mph. Mark Phelan, Detroit Free Press, 29 Feb. 2024
Noun
Most recently, on Jan. 22, 2024, India Prime Minister Narendra Modi inaugurated a Hindu temple in Ayodhya on the site of a mosque that had been built in 1528 but violently destroyed in 1992 by Hindu radicals, after a century of controversies over the land. Ahmet T. Kuru, The Conversation, 1 Mar. 2024 Bus drivers were too scared to ferry around a group of radicals. John Eligon Joao Silva, New York Times, 17 Feb. 2024 In the presence of nitrate radicals, significantly fewer moths visit primrose flowers. Popular Science, 8 Feb. 2024 In the process, these radicals damage cells and compounds such as DNA and proteins. Meghan Bartels, Scientific American, 17 Jan. 2024 In many ways, rock musician Wayne Kramer was a true radical. Steve Appleford, Rolling Stone, 17 Feb. 2024 Their methods showed that some of air pollution’s most common chemical agents—ozone and nitrate radicals—significantly deteriorate the wildflower’s scent, deterring the moths from landing on polluted plants. Christian Thorsberg, Smithsonian Magazine, 12 Feb. 2024 During his tenure, Pakistan witnessed a notable surge in Islamist militancy and the fortification of positions held by religious radicals. Kyra Colah, Fox News, 8 Feb. 2024 According to Camp, the hydrating salve is a solid choice for protecting mature skin from UV rays, as well as from free-oxygen radicals. Jenny Berg, Vogue, 1 Feb. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'radical.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

Adjective

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

First Known Use

Adjective

14th century, in the meaning defined at sense 1

Noun

1641, in the meaning defined at sense 1a

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

Dictionary Entries Near radical

Cite this Entry

“Radical.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radical. Accessed 19 Mar. 2024.

Kids Definition

radical

1 of 2 adjective
rad·​i·​cal ˈrad-i-kəl How to pronounce radical (audio)
1
: of, relating to, or proceeding from a root
2
a
: departing sharply from the usual or ordinary : extreme
b
: of or relating to radicals in politics
radically
-k(ə-)lē
adverb
radicalness noun

radical

2 of 2 noun
1
2
: a person who favors rapid and sweeping changes especially in laws and methods of government
3
: a group of atoms bonded together that is considered as a unit in various kinds of reactions
4
a
: a mathematical expression (as √͞ x) involving a radical sign
Etymology

Adjective

Middle English radical "relating to a root," from Latin radicalis (same meaning), from earlier radic-, radix "root" — related to eradicate, radish

Word Origin
Our word radical was formed from the Latin adjective radicalis, which simply meant "of or relating to a root." The Latin word radix meant "root." This meaning was kept when the word radicalis came into English as radical, but new senses developed too. Since a root is at the bottom of something, radical came to describe what is at the base or beginning, in other words, what is "basic, fundamental." Later, radical was used to describe something that was extremely different from the usual. Then, as a noun radical came to be applied to a person who wants to make extreme or "radical" changes in the government or in society. In mathematics, a radical sign indicates a root of a number. The words radish and eradicate also come from the Latin radix.

Medical Definition

radical

1 of 2 adjective
rad·​i·​cal ˈrad-i-kəl How to pronounce radical (audio)
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
radically adverb

radical

2 of 2 noun
: 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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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