Radical

adj. having extreme political views; fundamental, pertaining to a root; advocating complete reform

n. person with extreme political views; root of a number (Mathematics)

Radical (from Latin radicis, genitive of radix "root") can refer to many different things and concepts.
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Noun
1. (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
(synonym) group, chemical group
(hypernym) unit, building block
(hyponym) acyl, acyl group
(part-holonym) molecule
(classification) chemistry, chemical science
2. an atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule than has lost an electron and will stabilize itself by stealing an electron from a nearby molecule; "in the body free radicals are high-energy particles that ricochet wildly and damage cells"
(synonym) free radical
(hypernym) atom
3. a person who has radical ideas or opinions
(hypernym) person, individual, someone, somebody, mortal, human, soul
(hyponym) anarchist, nihilist, syndicalist
4. a character conveying the lexical meaning of a logogram
(hypernym) character, grapheme, graphic symbol
(part-holonym) ideogram, ideograph
5. a sign placed in front of an expression to denote that a root is to be extracted
(synonym) radical sign
(hypernym) mathematical notation
6. (linguistics) the form of a word after all affixes are removed; "thematic vowels are part of the stem"
(synonym) root, root word, base, stem, theme
(hypernym) form, word form, signifier, descriptor
(classification) linguistics
Adjective
1. (used of opinions and actions) far beyond the norm; "extremist political views"; "radical opinions on education"; "an ultra conservative"
(synonym) extremist, ultra
(similar) immoderate
2. markedly new or introducing radical change; "a revolutionary discovery"; "radical political views"
(synonym) revolutionary
(similar) new
3. arising from or going to the root; "a radical flaw in the plan"
(similar) basic
4. of or relating to or constituting a linguistic root; "a radical verb form"
(pertainym) root, root word, base, stem, theme
(classification) linguistics
5. especially of leaves; located at the base of a plant or stem; especially arising directly from the root or rootstock or a root-like stem; "basal placentation"; "radical leaves"
(synonym) basal
(antonym) cauline
(classification) botany, phytology

adj. radical, drastic

n. stem, radical, radix

adj. square root, number which is the total of a given number to the second power (i.e. the square root of 36 is 6 because 6 to the second power = 36); radical, pertaining to a root

n. radical, root of a number (Mathematics)