radical

[rad-i-kuhl]

adjective

1. of or going to the root or origin; fundamental.

   There is a radical difference between the two interpretations of the sacred text, one justifying war and the other requiring nonviolent resistance.

   Synonyms: ingrained, innate, original, essential, basic
   Antonyms: superficial

2. extreme, especially as regards change from accepted or traditional forms.

   a radical change in the policy of the company.

   Synonyms: violent, immoderate, excessive, drastic, thorough, unqualified, complete
   Antonyms: superficial

3. favoring drastic political, economic, or social reforms.

   radical ideas;

   radical and anarchistic ideologues.

4. favoring, supporting, or representing extreme forms of religious fundamentalism.

   radical fundamentalists and their rejection of modern science.

5. forming a basis or foundation.

   What is the radical reason for his choice?

6. existing inherently in a thing or person.

   radical defects of character.

7. characterized by a marked departure from prevailing methods, practices, or ideas, particularly in the arts; experimental; unorthodox.

   The composer’s radical approach to sound, using timbre and rhythm rather than pitch, was declared “noise” by an influential critic.

8. Slang.,  excellent; wonderful; cool; rad.

   You got here on an electric skateboard? That's radical!

9. Mathematics.

   1. pertaining to or forming a root.

   2. denoting or pertaining to the radical sign.

   3. irrational.

10. Grammar.,  of or pertaining to the root of a word.

11. Botany.,  of or arising from the root or the base of the stem.

noun

1. a person who holds or follows strong convictions or extreme principles; extremist.

2. a person who advocates fundamental political, economic, and social reforms by direct and often uncompromising methods.

3. 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.

4. Chemistry.

   1. group.

   2. free radical.

5. Grammar.,  root.

6. (in Chinese writing) one of 214 ideographic elements used in combination with phonetics to form thousands of different characters.

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,  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

1. a person who favours extreme or fundamental change in existing institutions or in political, social, or economic conditions

2. maths a root of a number or quantity, such as ³√5, √ x

3. Also: radicle. chem

   1. short for free radical

   2. another name for group

4. linguistics another word for root 1

5. (in logographic writing systems such as that used for Chinese) a part of a character conveying lexical meaning

radical

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

¹

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

radical

²

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

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

Other Word Forms

• radicalness noun
• radicality noun
• multiradical adjective
• nonradical adjective
• quasi-radical adjective
• semiradical adjective
• subradical adjective
• superradical adjective
• ultraradical adjective
• unradical adjective

Word History and Origins

Origin of radical¹

First recorded in 1350–1400; Middle English, from Late Latin rādīcālis “having roots, forming roots,” from Latin rādīc- (stem of rādix “root”) + -ālis -al ¹; root ¹

Word History and Origins

Origin of radical¹

C14: from Late Latin rādīcālis having roots, from Latin rādix a root

Synonym Study

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, especially in matters of religion or morality, has extravagant views and excessive zeal, rendering that person incapable of sound judgments and prone to take violent action against those who have differing views: fanatical in persecuting others.

Example Sentences

However, if you want this relationship to work, radical honesty about issues that matter to you are important.

Read more on MarketWatch

"All of this occurs in a larger global context where radical ideas are more mainstream and socially acceptable, manifested in this particular Croatian context," he said.

Read more on Barron's

In a tribute to the man who he described as "a radical and a pioneer", Rajan wrote that Sir Andreas had "profoundly transformed British journalism for the better, and forever."

Read more on BBC

"I think it's safe to say that change is on my agenda… Not overly radical, but changes that I think need to happen," he told Mr Levy.

Read more on BBC

The Red Scare followed—the government arrested and deported radicals, breaking unions like the IWW and hobbling labor for a decade.

Read more on The Wall Street Journal

Related Words

• agitator 
• anarchist 
• extremist 
• fanatic 
• firebrand 
• insurgent 
• leftist 
• militant 
• progressive 
• rebel 
• reformer 
• renegade 
• revolutionary 
• rioter www.thesaurus.com
• subversive