Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “radical”

radical

adjective uk   /ˈræd.ɪ.kəl/ us  

radical adjective (SUPPORTING CHANGE)

C2 believing or expressing the belief that there should be great or extreme social or political change: He was known as a radical reformer/thinker/politician. These people have very radical views.

radical adjective (VERY IMPORTANT)

C1 relating to the most important parts of something or someone; complete or extreme: We need to make some radical changes to our operating procedures. She has had to undergo radical surgery (= aimed at removing the cause of a disease).

radical adjective (extensive)

specialized medical aimed at removing all diseased tissue: Cervical cancer may be cured with radical surgery when it is confined to the pelvis or regional lymph nodes.
radically
adverb uk   /-i/ us  
C1 Barker introduced some radically new ideas.

radical

noun [C] uk   /ˈræd.ɪ.kəl/ us  
C2 a person who supports great social and political change: She was a radical all her life.
radicalism
noun [U] uk   /-ɪ.zəm/ us  
(Definition of radical from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of radical?
Add Cambridge dictionaries to your browser to your website

More meanings of “radical”

Definitions of “radical” in other dictionaries

Word of the Day

maiden

a girl or young woman

Word of the Day

Countability – grammar codes

by Dom Glennon​​,
November 26, 2014
Advices and informations Have you ever noticed strange codes in square brackets on entries in Cambridge Dictionaries Online and wondered what they mean? These are grammar codes, giving you a brief summary of how that word behaves grammatically. More information can be obtained by hovering your cursor over the code, and there’s

Read More 

ped-text verb

November 24, 2014
to text someone while walking I’m ped-texting, I’m looking down at my phone, 75 percent of the time.

Read More