What does radical mean?

Definitions for radical
ˈræd ɪ kəlrad·i·cal

This dictionary definitions page includes all the possible meanings, example usage and translations of the word radical.

Princeton's WordNet

  1. group, radical, chemical groupnoun

    (chemistry) two or more atoms bound together as a single unit and forming part of a molecule

  2. free radical, radicalnoun

    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

    "in the body free radicals are high-energy particles that ricochet wildly and damage cells"

  3. radicalnoun

    a person who has radical ideas or opinions

  4. radicalnoun

    (mathematics) a quantity expressed as the root of another quantity

  5. radicalnoun

    a character conveying the lexical meaning of a logogram

  6. root, root word, base, stem, theme, radicaladjective

    (linguistics) the form of a word after all affixes are removed

    "thematic vowels are part of the stem"

  7. extremist, radical, ultraadjective

    (used of opinions and actions) far beyond the norm

    "extremist political views"; "radical opinions on education"; "an ultra conservative"

  8. revolutionary, radicaladjective

    markedly new or introducing radical change

    "a revolutionary discovery"; "radical political views"

  9. radicaladjective

    arising from or going to the root or source

    "a radical flaw in the plan"

  10. radicaladjective

    of or relating to or constituting a linguistic root

    "a radical verb form"

  11. radical, basaladjective

    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"


  1. radicalnoun

    A member of the most progressive wing of the Liberal Party; someone favouring social reform (but generally stopping short of socialism).

  2. radicalnoun

    A member of an influential, centrist political party favouring moderate social reform, a republican constitution, and secular politics.

  3. radicalnoun

    A person with radical opinions.

  4. radicalnoun

    A root (of a number or quantity).

  5. radicalnoun

    In logographic writing systems as the Chinese writing system, the portion of a character (if any) that provides an indication of its meaning, as opposed to phonetic.

  6. radicalnoun

    In Semitic languages, any one of the set of consonants (typically three) that make up a root.

  7. radicalnoun

    A group of atoms, joined by covalent bonds, that take part in reactions as a single unit.

  8. radicalnoun

    A free radical.

  9. radicaladjective

    Favouring fundamental change, or change at the root cause of a matter.

    His beliefs are radical.

  10. radicaladjective

    Of or pertaining to a root .

  11. radicaladjective

    Of or pertaining to the intrinsic nature of something.

  12. radicaladjective


    The spread of the cancer required radical surgery, and the entire organ was removed.

  13. radicaladjective

    Of or pertaining to the root of a word.

  14. radicaladjective

    Involving free radicals

  15. radicaladjective


    That was a radical jump!

  16. Etymology: From radical, from radicalis, from radix; see radix.

Samuel Johnson's Dictionary

  1. RADICALadjective

    Etymology: radical, Fr. from radix, Latin.

    The differences, which are secondary and proceed from these radical differences, are, plants are all figurate and determinate, which inanimate bodies are not. Francis Bacon.

    Such a radical truth, that God is, springing up together with the essence of the soul, and previous to all other thoughts, is not pretended to by religion. Richard Bentley.

    The emission of the loose and adventitious moisture doth betray the radical moisture, and carrieth it for company. Francis Bacon.

    If the radical moisture of gold were separated, it might be contrived to burn without being consumed. John Wilkins.

    The sun beams render the humours hot, and dry up the radical moisture. Arbuthnot.


  1. radical

    In a general context, "radical" can have different meanings depending on the subject it is related to: 1. In general terms, it refers to something that advocates for complete social or political reform, representing extreme views, principles or ways of behaving. 2. In mathematics, a radical refers to a symbol that represents the root of a number, typically √. 3. In chemistry, it is used to describe an atom, molecule or ion that possesses unpaired valence electrons. 4. In linguistics, a radical is the part of a word that cannot be reduced any further into smaller components. 5. In botany, the term is used to describe the lower part of a plant embryo— the embryonic root. 6. In literature, a radical is an element of a word or language that inherently defines the word's main semantic characteristics. Each specific field of study may have its own specific definition of "radical", usually implying a central, fundamental or essential component, a drastic difference or deviation from tradition or accepted norms, or something relating to roots or origins.

Webster Dictionary

  1. Radicaladjective

    of or pertaining to the root; proceeding directly from the root

  2. Radicaladjective

    hence: Of or pertaining to the root or origin; reaching to the center, to the foundation, to the ultimate sources, to the principles, or the like; original; fundamental; thorough-going; unsparing; extreme; as, radical evils; radical reform; a radical party

  3. Radicaladjective

    belonging to, or proceeding from, the root of a plant; as, radical tubers or hairs

  4. Radicaladjective

    proceeding from a rootlike stem, or one which does not rise above the ground; as, the radical leaves of the dandelion and the sidesaddle flower

  5. Radicaladjective

    relating, or belonging, to the root, or ultimate source of derivation; as, a radical verbal form

  6. Radicaladjective

    of or pertaining to a radix or root; as, a radical quantity; a radical sign. See below

  7. Radicalnoun

    a primitive word; a radix, root, or simple, underived, uncompounded word; an etymon

  8. Radicalnoun

    a primitive letter; a letter that belongs to the radix

  9. Radicalnoun

    one who advocates radical changes in government or social institutions, especially such changes as are intended to level class inequalities; -- opposed to conservative

  10. Radicalnoun

    a characteristic, essential, and fundamental constituent of any compound; hence, sometimes, an atom

  11. Radicalnoun

    specifically, a group of two or more atoms, not completely saturated, which are so linked that their union implies certain properties, and are conveniently regarded as playing the part of a single atom; a residue; -- called also a compound radical. Cf. Residue

  12. Radicalnoun

    a radical quantity. See under Radical, a

  13. Radicaladjective

    a radical vessel. See under Radical, a


  1. Radical

    In chemistry, a radical is an atom, molecule, or ion that has unpaired valence electrons or an open electron shell, and therefore may be seen as having one or more "dangling" covalent bonds. With some exceptions, these "dangling" bonds make free radicals highly chemically reactive towards other substances, or even towards themselves: their molecules will often spontaneously dimerize or polymerize if they come in contact with each other. Most radicals are reasonably stable only at very low concentrations in inert media or in vacuum. A notable example of free radical is the hydroxyl radical, a molecule that is one hydrogen atom short of a water molecule and thus has one bond "dangling" from the oxygen. Two other examples are the carbene molecule, which has two dangling bonds; and the superoxide anion, the oxygen molecule O2 with one extra electron, which has one dangling bond. On the other hand, the hydroxyl anion, the oxide anion and the carbenium cation are not radicals, since the bonds that may appear to be dangling are in fact resolved by the addition or removal of electrons. Free radicals may be created in a number of ways, including synthesis with very dilute or rarefied reagents, reactions at very low temperatures, or breakup of larger molecules. The latter can be affected by any process that puts enough energy into the parent molecule, such as ionizing radiation, heat, electrical discharges, electrolysis, and chemical reactions. Indeed, radicals are intermediate stages in many chemical reactions.

Chambers 20th Century Dictionary

  1. Radical

    rad′i-kal, adj. pertaining to the root or origin: original: fundamental: intrinsic: primitive: implanted by nature: not derived: serving to originate: (bot.) proceeding immediately from the root: (politics) ultra-liberal, democratic.—n. a root: a primitive word or letter: one who advocates radical reform, an uncompromising democratic politician: (chem.) the base of a compound.—v.t. Rad′icalise, to make radical.—v.i. to become radical, adopt radical political principles.—n. Rad′icalism, the principles or spirit of a radical or democrat.—adv. Rad′ically.—n. Rad′icalness. [Radix.]

British National Corpus

  1. Spoken Corpus Frequency

    Rank popularity for the word 'radical' in Spoken Corpus Frequency: #2725

  2. Adjectives Frequency

    Rank popularity for the word 'radical' in Adjectives Frequency: #369

Anagrams for radical »

  1. aldaric

  2. cardial

How to pronounce radical?

How to say radical in sign language?


  1. Chaldean Numerology

    The numerical value of radical in Chaldean Numerology is: 6

  2. Pythagorean Numerology

    The numerical value of radical in Pythagorean Numerology is: 3

Examples of radical in a Sentence

  1. Russell Moore:

    Anyone who cares an iota about religious liberty should denounce this reckless, demagogic rhetoric, the government should close the borders to anyone suspected of even a passing involvement with any radical cell or terrorist network. But the government should not penalize law-abiding people, especially those who are American citizens, for holding their religious convictions.

  2. Donald Trump:

    Due to the fact that Democrats are unwilling to change our very dangerous immigration laws, we are indeed, as reported, giving strong considerations to placing Illegal Immigrants in Sanctuary Cities only, the Radical Left always seems to have Open Arms policy, Open Arms policy -- so this should make them very happy !

  3. Donald Trump:

    The tragic attacks in Paris prove once again that America needs to get tough on radical Islamic terrorism, president Obama and other politicians have consistently failed us.

  4. Marc Rylander:

    It is ridiculous that these activists are so dedicated to their radical pro-abortion agenda that they would sacrifice the health or lives of Texas women to further it.

  5. Mary Manin Boggs:

    My ideas are a curse. They spring from a radical discontent With the awful order of things.

Popularity rank by frequency of use


Translations for radical

From our Multilingual Translation Dictionary

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"radical." Definitions.net. STANDS4 LLC, 2024. Web. 20 May 2024. <https://www.definitions.net/definition/radical>.

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    candy and other sweets considered collectively
    A accident
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