Ultra-radical

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.

pertaining to or forming a root.
denoting or pertaining to the radical sign.
irrational (def 5b).

7.
Grammar. of or relating 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.

a quantity expressed as a root of another quantity.
the set of elements of a ring, some power of which is contained in a given ideal.
radical sign.

12.
Chemistry.

group (def 3).
free radical.

13.
Grammar. root1 (def 12).
14.
(in Chinese writing) one of 214 ideographic elements used in combination with phonetics to form thousands of different characters.
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

short for free radical
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

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

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

A free radical.

adj.

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

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

radical
(rād’ĭ-kəl)

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

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 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.