Definitions for radical
ˈræd ɪ kəlrad·i·cal

Princeton's WordNet(4.50 / 2 votes)Rate this definition:

1. group, radical, chemical group(noun)

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

2. free radical, radical(noun)

   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. radical(noun)

   a person who has radical ideas or opinions

4. radical(noun)

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

5. radical(noun)

   a character conveying the lexical meaning of a logogram

6. root, root word, base, stem, theme, radical(adj)

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

   "thematic vowels are part of the stem"

7. extremist, radical, ultra(adj)

   (used of opinions and actions) far beyond the norm

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

8. revolutionary, radical(adj)

   markedly new or introducing radical change

   "a revolutionary discovery"; "radical political views"

9. radical(adj)

   arising from or going to the root or source

   "a radical flaw in the plan"

10. radical(adj)

    of or relating to or constituting a linguistic root

    "a radical verb form"

11. radical, basal(adj)

    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"

Wiktionary(0.00 / 0 votes)Rate this definition:

1. radical(Noun)

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

2. radical(Noun)

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

3. radical(Noun)

   A person with radical opinions.

4. radical(Noun)

   A root (of a number or quantity).

5. radical(Noun)

   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. radical(Noun)

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

7. radical(Noun)

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

8. radical(Noun)

   A free radical.

9. radical(Adjective)

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

   His beliefs are radical.

10. radical(Adjective)

    Of or pertaining to a root .

11. radical(Adjective)

    Of or pertaining to the intrinsic nature of something.

12. radical(Adjective)

    Thoroughgoing.

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

13. radical(Adjective)

    Of or pertaining to the root of a word.

14. radical(Adjective)

    Involving free radicals

15. radical(Adjective)

    Excellent.

    That was a radical jump!

Origin: From radical, from radicalis, from radix; see radix.

Webster Dictionary(0.00 / 0 votes)Rate this definition:

1. Radical(adj)

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

2. Radical(adj)

   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. Radical(adj)

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

4. Radical(adj)

   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. Radical(adj)

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

6. Radical(adj)

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

7. Radical(noun)

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

8. Radical(noun)

   a primitive letter; a letter that belongs to the radix

9. Radical(noun)

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

10. Radical(noun)

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

11. Radical(noun)

    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. Radical(noun)

    a radical quantity. See under Radical, a

13. Radical(adj)

    a radical vessel. See under Radical, a

Freebase(0.00 / 0 votes)Rate this definition:

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(0.00 / 0 votes)Rate this definition:

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

How to pronounce radical?

1. 

   Alex

   US English

   

   Daniel

   British

   

   Karen

   Australian

   

   Veena

   Indian

How to say radical in sign language?

Numerology

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. Lenin:

   Be as radical as reality.

2. Texas Sen. Ted Cruz:

   Radical Islam is at war with us.

3. Hillary Clinton:

   We are at war with radical Islam.

4. German Gref:

   We need a radical turn in economic policy.

5. Michael Burke:

   This is not a very radical thing here on campus.

Images & Illustrations of radical

Popularity rank by frequency of use