radical

[rad-i-kuh l] /ˈræd ɪ kəl/
adjective
1.
of or going to the root or origin; fundamental:
a radical difference.
2.
thoroughgoing or extreme, especially as regards change from accepted or traditional forms:
a radical change in the policy of a company.
3.
favoring drastic political, economic, or social reforms:
radical ideas; radical and anarchistic ideologues.
4.
forming a basis or foundation.
5.
existing inherently in a thing or person:
radical defects of character.
6.
Mathematics.
  1. pertaining to or forming a root.
  2. denoting or pertaining to the radical sign.
  3. irrational (def 5b).
7.
Grammar. of or pertaining to a root.
8.
Botany. of or arising from the root or the base of the stem.
noun
9.
a person who holds or follows strong convictions or extreme principles; extremist.
10.
a person who advocates fundamental political, economic, and social reforms by direct and often uncompromising methods.
11.
Mathematics.
  1. a quantity expressed as a root of another quantity.
  2. the set of elements of a ring, some power of which is contained in a given ideal.
  3. radical sign.
12.
Chemistry.
  1. group (def 3).
  2. free radical.
13.
Grammar, root (def 11).
14.
(in Chinese writing) one of 214 ideographic elements used in combination with phonetics to form thousands of different characters.
Origin
1350-1400; Middle English < Late Latin rādīcālis having roots, equivalent to Latin rādīc- (stem of rādīx) root1 + -ālis -al1
Related forms
radicalness, noun
half-radical, adjective
half-radically, adverb
multiradical, adjective
nonradical, adjective, noun
nonradicalness, noun
quasi-radical, adjective
quasi-radically, adverb
semiradical, adjective
semiradically, adverb
semiradicalness, noun
subradical, adjective
subradicalness, noun
superradical, adjective
superradically, adverb
superradicalness, noun
ultraradical, adjective, noun
ultraradically, adverb
unradical, adjective
unradically, adverb
Synonyms
1. basic, essential; original, innate, ingrained. 2. complete, unqualified, thorough; drastic, excessive, immoderate, violent. Radical, extreme, fanatical denote that which goes beyond moderation or even to excess in opinion, belief, action, etc. Radical emphasizes the idea of going to the root of a matter, and this often seems immoderate in its thoroughness or completeness: radical ideas; radical changes or reforms. Extreme applies to excessively biased ideas, intemperate conduct, or repressive legislation: to use extreme measures. Fanatical is applied to a person who has extravagant views, especially in matters of religion or morality, which render that person incapable of sound judgments; and excessive zeal which leads him or her to take violent action against those who have differing views: fanatical in persecuting others.
Antonyms
1, 2. superficial.
Examples from the web for radical
  • Both of them seem unfazed by this radical change in their physiologies.
  • The whole system must before long undergo a radical change.
  • Both they and their voters avoid radical change whenever possible.
  • When it comes to the fate of academic freedom, don't count me in for fostering such a radical change.
  • When it comes to radical energy solutions, an extreme long shot is a nuclear power scheme that would combine fusion and fission.
  • It might be uncomfortable and take a bit of work, but our future depends on this radical change in order to survive.
  • Moreover, such a change would in fact be less radical than it might at first appear.
  • It will require people to change many things in their lives, and will also cause radical changes in our economy.
  • King's prided itself on the enthusiasm with which it embraced change and radical disruption.
  • Despite the difficulty of this technique, he burnished out parts of the composition and made radical changes.
British Dictionary definitions for radical

radical

/ˈrædɪkəl/
adjective
1.
of, relating to, or characteristic of the basic or inherent constitution of a person or thing; fundamental: a radical fault
2.
concerned with or tending to concentrate on fundamental aspects of a matter; searching or thoroughgoing: radical thought, a radical re-examination
3.
favouring or tending to produce extreme or fundamental changes in political, economic, or social conditions, institutions, habits of mind, etc: a radical party
4.
(med) (of treatment) aimed at removing the source of a disease: radical surgery
5.
(slang, mainly US) very good; excellent
6.
of, relating to, or arising from the root or the base of the stem of a plant: radical leaves
7.
(maths) of, relating to, or containing roots of numbers or quantities
8.
(linguistics) of or relating to the root of a word
noun
9.
a person who favours extreme or fundamental change in existing institutions or in political, social, or economic conditions
10.
(maths) a root of a number or quantity, such as ³√5, √x
11.
(chem) Also radicle
  1. short for free radical
  2. another name for group (sense 10)
12.
(linguistics) another word for root1 (sense 9)
13.
(in logographic writing systems such as that used for Chinese) a part of a character conveying lexical meaning
Derived Forms
radicalness, noun
Word Origin
C14: from Late Latin rādīcālis having roots, from Latin rādix a root
Word Origin and History for radical
adj.

late 14c., in a medieval philosophical sense, from Late Latin radicalis "of or having roots," from Latin radix (genitive radicis) "root" (see radish). Meaning "going to the origin, essential" is from 1650s. Radical sign in mathematics is from 1680s.

Political sense of "reformist" (via notion of "change from the roots") is first recorded 1802 (n.), 1817 (adj.), of the extreme section of the British Liberal party (radical reform had been a current phrase since 1786); meaning "unconventional" is from 1921. U.S. youth slang use is from 1983, from 1970s surfer slang meaning "at the limits of control." Radical chic is attested from 1970; popularized, if not coined, by Tom Wolfe. Radical empiricism coined 1897 by William James (see empiricism).

n.

1630s, "root part of a word, from radical (adj.) Political sense from 1802; chemical sense from 1816.

radical in Medicine

radical rad·i·cal (rād'ĭ-kəl)
n.
Abbr. R

  1. A group of elements or atoms usually passing intact from one compound to another but generally incapable of prolonged existence in a free state.

  2. A free radical.

adj.

  1. Of or being medical treatment by extreme, drastic, or innovative measures.

  2. Designed to act on or eliminate the root or cause of a pathological process.

radical in Science
radical
  (rād'ĭ-kəl)   

  1. A root, such as √2, especially as indicated by a radical sign (√).

  2. A group of atoms that behaves as a unit in chemical reactions and is often not stable except as part of a molecule. The hydroxyl, ethyl, and phenyl radicals are examples. Radicals are unchanged by chemical reactions.


radical in Culture

radical definition


In politics, someone who demands substantial or extreme changes in the existing system.

radical definition


In chemistry, an atom or group of atoms that has at least one electron free to participate in forming a chemical bond.

Note: In general, radicals are associated with chemical reactions that proceed rapidly.