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RADICAL
| Pronunciation (US): |  | (GB): | |
I. (noun)
Sense 1
Meaning:
(linguistics) the form of a word after all affixes are removed
Example:
thematic vowels are part of the stem
Synonyms:
base; radical; root; root word; stem; theme
Classified under:
Nouns denoting communicative processes and contents
Hypernyms ("radical" is a kind of...):
descriptor; form; signifier; word form (the phonological or orthographic sound or appearance of a word that can be used to describe or identify something)
Domain category:
linguistics (the scientific study of language)
Sense 2
Meaning:
A character conveying the lexical meaning of a logogram
Classified under:
Nouns denoting communicative processes and contents
Hypernyms ("radical" is a kind of...):
character; graph; grapheme; graphic symbol (a written symbol that is used to represent speech)
Holonyms ("radical" is a part of...):
ideogram; ideograph (a graphic character that indicates the meaning of a thing without indicating the sounds used to say it)
Sense 3
Meaning:
A person who has radical ideas or opinions
Classified under:
Hypernyms ("radical" is a kind of...):
individual; mortal; person; somebody; someone; soul (a human being)
Hyponyms (each of the following is a kind of "radical"):
young Turk (a young radical who agitates for reform)
Wobbly (a member of the Industrial Workers of the World)
Trot; Trotskyist; Trotskyite (radicals who support Trotsky's theory that socialism must be established throughout the world by continuing revolution)
terrorist (a radical who employs terror as a political weapon; usually organizes with other terrorists in small cells; often uses religion as a cover for terrorist activities)
revolutionary; revolutionist; subversive; subverter (a radical supporter of political or social revolution)
leveler; leveller (a radical who advocates the abolition of social distinctions)
extremist (a person who holds extreme views)
Bolshevik; bolshie; bolshy; Marxist; red (emotionally charged terms used to refer to extreme radicals or revolutionaries)
anarchist; nihilist; syndicalist (an advocate of anarchism)
Sense 4
Meaning:
(mathematics) a quantity expressed as the root of another quantity
Classified under:
Nouns denoting quantities and units of measure
Hypernyms ("radical" is a kind of...):
amount; measure; quantity (how much there is or how many there are of something that you can quantify)
Domain category:
math; mathematics; maths (a science (or group of related sciences) dealing with the logic of quantity and shape and arrangement)
Sense 5
Meaning:
(chemistry) two or more atoms bound together as a single unit and forming part of a molecule
Synonyms:
chemical group; group; radical
Classified under:
Hypernyms ("radical" is a kind of...):
building block; unit (a single undivided natural thing occurring in the composition of something else)
Domain category:
chemical science; chemistry (the science of matter; the branch of the natural sciences dealing with the composition of substances and their properties and reactions)
Hyponyms (each of the following is a kind of "radical"):
carboxyl; carboxyl group (the univalent radical -COOH; present in and characteristic of organic acids)
chromophore (the chemical group that gives color to a molecule)
cyanide group; cyanide radical; cyano group; cyano radical (the monovalent group -CN in a chemical compound)
glyceryl (a trivalent radical derived from glycerol by removing the three hydroxyl radicals)
hydrazo group; hydrazo radical (the bivalent group -HNNH- derived from hydrazine)
hydroxyl; hydroxyl group; hydroxyl radical (the monovalent group -OH in such compounds as bases and some acids and alcohols)
ketone group (a group having the characteristic properties of ketones)
methylene; methylene group; methylene radical (the bivalent radical CH2 derived from methane)
propyl; propyl group; propyl radical (the monovalent organic group C3H7- obtained from propane)
butyl (a hydrocarbon radical (C4H9))
nitro group (the group -NO3)
nitrite (the radical -NO2 or any compound containing it (such as a salt or ester of nitrous acid))
uranyl; uranyl group; uranyl radical (the bivalent radical UO2 which forms salts with acids)
vinyl; vinyl group; vinyl radical (a univalent chemical radical derived from ethylene)
carbonyl group (the bivalent radical CO)
arsenic group; cacodyl; cacodyl group; cacodyl radical (the univalent group derived from arsine)
benzoyl group; benzoyl radical (the univalent radical derived from benzoic acid)
benzyl; benzyl group; benzyl radical (the univalent radical derived from toluene)
azo group; azo radical (the bivalent group -N=N- united to two hydrocarbon groups)
azido group; azido radical (the univalent group N3- derived from hydrazoic acid)
amyl (a hydrocarbon radical that occurs in many organic compounds)
amino; amino group (the radical -NH2)
allyl; allyl group; allyl radical (the univalent unsaturated organic radical C3H5; derived from propylene)
alkyl; alkyl group; alkyl radical (any of a series of univalent groups of the general formula CnH2n+1 derived from aliphatic hydrocarbons)
aldehyde group; aldehyde radical (the chemical group -CHO)
alcohol group; alcohol radical (the chemical group -OH)
acyl; acyl group (any group or radical of the form RCO- where R is an organic group)
Holonyms ("radical" is a part of...):
molecule ((physics and chemistry) the simplest structural unit of an element or compound)
Sense 6
Meaning:
An atom or group of atoms with at least one unpaired electron; in the body it is usually an oxygen molecule that has lost an electron and will stabilize itself by stealing an electron from a nearby molecule
Example:
in the body free radicals are high-energy particles that ricochet wildly and damage cells
Synonyms:
free radical; radical
Classified under:
Nouns denoting substances
Hypernyms ("radical" is a kind of...):
atom ((physics and chemistry) the smallest component of an element having the chemical properties of the element)
II. (adjective)
Sense 1
Meaning:
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
Example:
radical leaves
Synonyms:
basal; radical
Classified under:
Domain category:
botany; phytology (the branch of biology that studies plants)
Antonym:
cauline (especially of leaves; growing on a stem especially on the upper part of a stem)
Sense 2
Meaning:
(used of opinions and actions) far beyond the norm
Example:
an ultra conservative
Synonyms:
extremist; radical; ultra
Classified under:
Similar:
immoderate (beyond reasonable limits)
Sense 3
Meaning:
Markedly new or introducing radical change
Example:
radical political views
Synonyms:
radical; revolutionary
Classified under:
Adjectives
Similar:
new (not of long duration; having just (or relatively recently) come into being or been made or acquired or discovered)
Sense 4
Meaning:
Arising from or going to the root or source
Example:
a radical flaw in the plan
Classified under:
Adjectives
Similar:
basic (pertaining to or constituting a base or basis)
Sense 5
Meaning:
Of or relating to or constituting a linguistic root
Example:
a radical verb form
Classified under:
Relational adjectives (pertainyms)
Domain category:
linguistics (the scientific study of language)
Pertainym:
root ((linguistics) the form of a word after all affixes are removed)
Context examples:
A group of organic or inorganic substances capable of preventing the genotoxic and carcinogenic effects of free-radical compounds.
(Antioxidant, NCI Thesaurus)
Within mitochondria, mutant SOD1 may interfere with the anti-apoptotic function of Bcl-2, affect mitochondrial import by interfering with the translocation machinery (TOM/TIM), and generate toxic free radicals (ROS) via aberrant superoxide chemistry.
(Amyotrophic Lateral Sclerosis Pathway, NCI Thesaurus/KEGG)
A substance that protects cells from the damage caused by free radicals (unstable molecules made by the process of oxidation during normal metabolism).
(Antioxidant, NCI Dictionary)
Treatment with antioxidants in order to protect cells against damage caused by oxygen-free radicals.
(Antioxidants Therapy, NCI Thesaurus)
Exhibiting high electron affinity, misonidazole induces the formation of free radicals and depletes radioprotective thiols, thereby sensitizing hypoxic cells to the cytotoxic effects of ionizing radiation.
(Misonidazole, NCI Thesaurus)
In addition, nifurtimox-derived nitro anion free radicals may alkylate macromolecules such as nucleic acids and proteins, resulting in the disruption of their structure and function.
(Nifurtimox, NCI Thesaurus)
An unstable free-radical gas which reacts rapidly with oxygen to form nitrogen oxides.
(Nitric Oxide, NCI Thesaurus)
A free radical gas produced endogenously by a variety of mammalian cells.
(Nitric Oxide, NLM, Medical Subject Headings)
Organic compounds containing the -CN radical.
(Nitriles, NLM, Medical Subject Headings)
These genes help protect the cell from damage caused by free radicals (unstable molecules made during normal cell metabolism).
(NFE2L2, NCI Dictionary)
