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# radical

«radical» in Mova's school dictionary: **Very big and basic, changing the most important parts of…** — its meaning for a pupil, its sense in the lessons and examples.

### part of speech

adjective (radical, more radical, most radical); noun (a radical, radicals)

### meaning for a pupil

1) Very big and basic, changing the most important parts of something: a radical change. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#m1)

2) Having very strong or extreme ideas about how society or politics should change. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#m2)

3) (noun) A person with extreme political ideas. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#m3)

4) (maths) To do with roots, such as the square root sign √, which is called the radical sign. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#m4)

5) (science) A free radical is an atom or group of atoms with an unpaired electron, which reacts easily. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#m5)

6) (slang, US, dated) Really cool or amazing — "Radical, dude!" [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#m6)

### sense in the lessons

In everyday life, a radical change is a huge one, like moving to a new country. In politics and history lessons, radicals were people who wanted big changes fast, sometimes peaceful, sometimes violent. In maths, the radical sign √ shows a square root: √16 = 4. In stories, a "radical" character challenges how things are. Phrases: radical change, radical idea, radical sign, free radical.

### examples

- The new head teacher made radical changes to the timetable. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#x1)
- Moving from the city to a farm was a radical change for our family. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#x2)
- Some radicals wanted to get rid of the king. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#x3)
- In maths, the radical sign √ means "square root of". [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#x4)
- √25 is called a radical expression, and it equals 5. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#x5)
- "That skateboard trick was radical!" shouted the surfer dude. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#x6)
- Her idea to have no homework at all seemed radical to the teachers. [tree →](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/#x7)

### note

"Radical" comes from Latin "radix", meaning root — so a radical change goes right to the roots. In maths, √ is the radical sign: √9 = 3 because 3 × 3 = 9. The slang meaning "cool" is old-fashioned 1980s surfer talk, now mostly a joke. Adverb: radically.

### Trees and pragmatics

[Every meaning and example of «radical» parsed by Mova](https://md.mova.elamur.ai/free/en/corpora/dictionaries/school/R/radical/), each sentence with its dependency tree and frames.