Radical definition

rădĭ-kəl
Frequency:
Relating to or advocating fundamental or revolutionary changes in current practices, conditions, or institutions.

Radical politics; a radical political theorist.

adjective
16
3
(mathematics) The root of a quantity as indicated by the radical sign.
noun
14
1
Departing markedly from the usual or customary; extreme or drastic.

A radical change in diet.

adjective
11
3
Departing markedly from the usual or customary; extreme or drastic.

A radical change in diet.

adjective
10
3
An atom or a group of atoms with one unpaired electron.
noun
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1
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(medicine) Relating to or being surgery that is extreme or drastic in an effort to eradicate all existing or potential disease.

Radical hysterectomy.

adjective
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2
(linguistics) Of or being a root.

A radical form.

adjective
5
0
Arising from or going to a root or source; basic.

Proposed a radical solution to the problem.

adjective
5
2
A root, such as √2, especially as indicated by a radical sign (√).
4
1
Favoring fundamental change, or change at the root cause of a matter.

His beliefs are radical.

adjective
4
1
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One who advocates fundamental or revolutionary changes in current practices, conditions, or institutions.

Radicals seeking to overthrow the social order.

noun
3
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.
2
1
(botany, not comparable) Pertaining to a root (of a plant).
adjective
2
1
Pertaining to the basic or intrinsic nature of something.
adjective
2
1
(mathematics) Relating to a radix or mathematical root.

A radical quantity; a radical sign.

adjective
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1
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(arithmetic) A root (of a number or quantity).
noun
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1
(linguistics) In logographic writing systems as the Chinese writing system, the portion of a character (if any) that provides an indication of its meaning, as opposed to phonetic.
noun
1
1
(linguistics) In Semitic languages, any one of the set of consonants (typically three) that make up a root.
noun
1
1
(chemistry) A group of atoms, joined by covalent bonds, that take part in reactions as a single unit.
noun
1
1
Of, relating to, or arising from a root.

Radical hairs.

adjective
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Arising from the base of a stem or from a below-ground stem or rhizome.

Radical leaves.

adjective
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Any of the basic Chinese characters that are combined to form more complex characters.
noun
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Any of the traditional set of basic strokes or groups of strokes that make up Chinese characters and are used to classify and organize them in dictionaries.
noun
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(bot.) Of or coming from the root.
adjective
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(math.) Having to do with the root or roots of a number or quantity.
adjective
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Of or from the root or roots; going to the foundation or source of something; fundamental; basic.

A radical principle.

adjective
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Extreme; thorough.

A radical change in one's life.

adjective
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Favoring fundamental or extreme change; specif., favoring basic change in the social or economic structure.
adjective
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Designating or of any of various modern political parties, esp. in Europe, ranging from moderate to conservative in program.
adjective
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(chem.) A group of two or more atoms that acts as a single atom and goes through a reaction unchanged, or is replaced by a single atom: it is normally incapable of separate existence.
noun
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A basic or root part of something.
noun
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A fundamental.
noun
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A person holding radical views, esp. one favoring fundamental social or economic change.
noun
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A member or adherent of a Radical party.
noun
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The indicated root of a quantity or quantities, shown by an expression written under the radical sign.
noun
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Relating to or arising from a root.

Radical hairs.

adjective
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0
Arising from the base of a stem or from a below-ground stem or rhizome.

Radical leaves.

adjective
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Radical is someone who goes against social norms and who often advocates social change.

An example of a radical was a hippie in the 1960's.

noun
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1
(slang) Excellent; wonderful.
adjective
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1
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(medicine) Relating to or being surgery that is extreme or drastic in an effort to eradicate all existing or potential disease.

Radical hysterectomy.

adjective
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1

The spread of the cancer required radical surgery, and the entire organ was removed.

adjective
0
1
(linguistics, not comparable) Of or pertaining to the root of a word.
adjective
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1
(linguistics, not comparable, of a sound) Produced using the root of the tongue.
adjective
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1
(chemistry, not comparable) Involving free radicals.
adjective
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1
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(slang, 1990s) Excellent; awesome.

That was a radical jump!

adjective
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1
(historical: 19th-century England) A member of the most progressive wing of the Liberal Party; someone favouring social reform (but generally stopping short of socialism).
noun
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1
(historical: early 20th-century France) A member of an influential, centrist political party favouring moderate social reform, a republican constitution, and secular politics.
noun
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A person with radical opinions.
noun
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1
(organic chemistry) A free radical.
noun
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1
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The definition of radical is something that is at the root of something, or something that changes, addresses or affects the major essence of something.

An example of radical is a basic solution to a complex problem.

An example of radical is the change that allowed women to vote.

adjective
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2

Other Word Forms

Noun

Singular:
radical
Plural:
radicals

Origin of radical

  • Middle English of a root from Late Latin rādīcālis having roots from Latin rādīx rādīc- root wrād- in Indo-European roots

    From American Heritage Dictionary of the English Language, 5th Edition

  • From French radical, from Late Latin radicalis (“of or pertaining to the root, having roots, radical"), from Latin radix (“root"); see radix.

    From Wiktionary