Radical may refer to:

Politics and ideology

Politics

* Radical politics, the political intent of fundamental societal change * Radicalism (historical), the Radical Movement that began in late 18th century Britain and spread to continental Europe and Latin America in the 19th century *

Radical Party (disambiguation) Radical Party may refer to any of a number of political parties professing the progressive-liberal ideology known as Radicalism: Worldwide * Nonviolent Radical Party Transnational and Transparty (1989–present) Europe In the western Mediterra ...

, several political parties * Radicals (UK), a British and Irish grouping in the early to mid-19th century * Radicalization

Ideologies

Radical chic Radical chic is the fashionable practice of upper-class people associating with politically radical people and causes. Coined in the 1970 article "Radical Chic: That Party at Lenny's" by journalist Tom Wolfe, the term has become widely used in l ...

, a term coined by Tom Wolfe to describe the pretentious adoption of radical causes *

Radical feminism Radical feminism is a perspective within feminism that calls for a radical re-ordering of society in which male supremacy is eliminated in all social and economic contexts, while recognizing that women's experiences are also affected by other s ...

, a perspective within feminism that focuses on patriarchy * Radical Islam, or Islamic extremism * Radical veganism, a radical interpretation of veganism, usually combined with anarchism *

Radical Reformation The Radical Reformation represented a response to corruption both in the Catholic Church and in the expanding Magisterial Protestant movement led by Martin Luther and many others. Beginning in Germany and Switzerland in the 16th century, the R ...

, an Anabaptist movement concurrent with the Protestant Reformation

Science and mathematics

Science

Radical (chemistry) In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spont ...

, an atom, molecule, or ion with unpaired valence electron(s) *

Radical surgery Radical surgery, also called radical dissection, is surgery that is more extensive than "conservative" surgery. In surgical oncology, radical surgery is surgery intended to remove both a tumor and any metastases thereof, for diagnostic and/or tr ...

, where diseased tissue or lymph nodes are removed from a diseased organ

Mathematics

Radical expression In mathematics, a radicand, also known as an nth root, of a number ''x'' is a number ''r'' which, when raised to the power ''n'', yields ''x'': :r^n = x, where ''n'' is a positive integer, sometimes called the ''degree'' of the root. A ro ...

involving roots, also known as an ''n''th root * Radical symbol (√), used to indicate the square root and other roots *

Radical of an algebraic group The radical of an algebraic group is the identity component of its maximal normal subgroup, normal solvable group, solvable subgroup. For example, the radical of the general linear group \operatorname_n(K) (for a field ''K'') is the subgroup consist ...

, a concept in algebraic group theory * Radical of an ideal, an important concept in abstract algebra *

Radical of a ring In ring theory, a branch of mathematics, a radical of a ring is an ideal of "not-good" elements of the ring. The first example of a radical was the nilradical introduced by , based on a suggestion of . In the next few years several other radical ...

, an ideal of "bad" elements of a ring ** Jacobson radical, consisting of those elements in a ring R that annihilate all simple right R-modules ** Nilradical of a ring, a nilpotent ideal which is as large as possible * Radical of a module, a component in the theory of structure and classification * Radical of an integer, in number theory, the product of the primes which divide an integer *

Radical of a Lie algebra In the mathematical field of Lie theory, the radical of a Lie algebra \mathfrak is the largest solvable ideal of \mathfrak.. The radical, denoted by (\mathfrak), fits into the exact sequence :0 \to (\mathfrak) \to \mathfrak g \to \mathfrak/(\math ...

, a concept in Lie theory **

Nilradical of a Lie algebra In algebra, the nilradical of a Lie algebra is a nilpotent ideal, which is as large as possible. The nilradical \mathfrak(\mathfrak g) of a finite-dimensional Lie algebra \mathfrak is its maximal nilpotent ideal, which exists because the sum of a ...

, a nilpotent ideal which is as large as possible *Left (or right) radical of a

bilinear form In mathematics, a bilinear form is a bilinear map on a vector space (the elements of which are called '' vectors'') over a field ''K'' (the elements of which are called ''scalars''). In other words, a bilinear form is a function that is linear ...

, the subspace of all vectors left (or right) orthogonal to every vector

Linguistics

* Root (linguistics), also called a "radical", the form of a word after any prefixes and suffixes are removed * Radical (Chinese characters), part of a Chinese character * Radical consonant, a pharyngeal consonant *Radical, one of the three consonants in a

Semitic root The roots of verbs and most nouns in the Semitic languages are characterized as a sequence of consonants or " radicals" (hence the term consonantal root). Such abstract consonantal roots are used in the formation of actual words by adding the vowe ...

Arts and entertainment

Music

* ''Radical'' (mixtape), by Odd Future, 2010 * ''Radical'' (Every Time I Die album), 2021 * ''Radical'' (Smack album), 1988 *"Radicals", a song by Tyler, The Creator from the 2011 album '' Goblin''

Architecture and design

* Radical period (design), a period in late 1960s Italian design * Radical Baroque, an architectural style

Literature

*'' Radical: My Journey out of Islamist Extremism'', by Maajid Nawaz, 2013 * ''Radical'' (book), by David Platt, 2010

Other uses

* Radical, Missouri, U.S., a ghost town *

Radical, North Carolina Radical is an unincorporated area in Wilkes County, North Carolina. History A post office A post office is a public facility and a retailer that provides mail services, such as accepting letters and parcels, providing post office boxes, and ...

, U.S. * Radical Sportscars, a British sports car maker * Radical Entertainment, a Canadian video game developer * Radical.fm, a digital music streaming service