¹radical

adjective rad·i·cal \ˈra-di-kəl\

: 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

Full Definition of RADICAL

: of, relating to, or proceeding from a root: 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>

: of or relating to the origin : fundamental

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>

slang : excellent, cool

— rad·i·cal·ness noun

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Origin of RADICAL

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

First Known Use: 14th century

Related to RADICAL

Synonyms: extremist, fanatic (or fanatical), rabid, extreme, revolutionary, revolutionist, ultra

Antonyms: middle-of-the-road, nonrevolutionary, unrevolutionary

²radical

noun

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

Full Definition of RADICAL

a : a root part

b : a basic principle : foundation

a : root 6

b : a sound or letter belonging to a radical

: one who is radical

: 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

a : a mathematical expression indicating a root by means of a radical sign

b : radical sign

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