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Meaning of RADICAL

Pronunciation:  'radikul

WordNet Dictionary
  1. [n]  (linguistics) the form of a word after all affixes are removed; "thematic vowels are part of the stem"
  2. [n]  a sign placed in front of an expression to denote that a root is to be extracted
  3. [n]  a character conveying the lexical meaning of a logogram
  4. [n]  a person who has radical ideas or opinions
  5. [n]  (chemistry) two or more atoms bound together as a single unit and forming part of a molecule
  6. [n]  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"
  7. [adj]  (botany) 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"
  8. [adj]  (used of opinions and actions) far beyond the norm; "extremist political views"; "radical opinions on education"; "an ultra conservative"
  9. [adj]  markedly new or introducing radical change; "a revolutionary discovery"; "radical political views"
  10. [adj]  arising from or going to the root; "a radical flaw in the plan"
  11. [adj]  (linguistics) of or relating to or constituting a linguistic root; "a radical verb form"

RADICAL is a 7 letter word that starts with R.


 Synonyms: basal, base, basic, chemical group, extremist, free radical, group, immoderate, new, radical sign, revolutionary, root, root, root word, stem, theme, ultra
 Antonyms: cauline
 See Also: acyl, acyl group, alcohol group, alcohol radical, aldehyde group, aldehyde radical, alkyl, alkyl group, alkyl radical, allyl, allyl group, allyl radical, amino, amino group, anarchist, arsenic group, atom, azido group, azido radical, azo group, azo radical, benzoyl group, benzoyl radical, benzyl, benzyl group, benzyl radical, Bolshevik, bolshie, building block, cacodyl, cacodyl group, cacodyl radical, carbonyl group, carboxyl, carboxyl group, character, chromophore, controversialist, cyanide group, cyanide radical, cyano group, cyano radical, disputant, extremist, form, glyceryl, grapheme, graphic symbol, hydrazo group, hydrazo radical, hydroxyl, hydroxyl group, hydroxyl radical, ideogram, ideograph, ketone group, leveler, leveller, Marxist, mathematical notation, methylene, methylene group, methylene radical, molecule, nihilist, nitrite, nitro group, pinko, propyl, propyl group, propyl radical, red, revolutionary, revolutionist, signifier, subversive, subverter, syndicalist, terrorist, Trot, Trotskyist, Trotskyite, unit, uranyl, uranyl group, uranyl radical, vinyl, vinyl group, vinyl radical, word form, Young Turk



Webster's 1913 Dictionary
  1. \Rad"i*cal\, a. [F., fr. L. radicalis having roots, fr.
    radix, -icis, a root. See {Radix}.]
    1. Of or pertaining to the root; proceeding directly from the
    2. 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.
             The most determined exertions of that authority,
             against them, only showed their radical
             independence.                         --Burke.
    3. (Bot.)
       (a) Belonging to, or proceeding from, the root of a plant;
           as, radical tubers or hairs.
       (b) 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.
    4. (Philol.) Relating, or belonging, to the root, or ultimate
       source of derivation; as, a radical verbal form.
    5. (Math.) Of or pertaining to a radix or root; as, a radical
       quantity; a radical sign. See below.
    {Radical axis of two circles}. (Geom.) See under {Axis}.
    {Radical pitch}, the pitch or tone with which the utterance
       of a syllable begins. --Rush.
    {Radical quantity} (Alg.), a quantity to which the radical
       sign is prefixed; specifically, a quantity which is not a
       perfect power of the degree indicated by the radical sign;
       a surd.
    {Radical sign} (Math.), the sign [root] (originally the
       letter r, the initial of radix, root), placed before any
       quantity, denoting that its root is to be extracted; thus,
       [root]a, or [root](a + b). To indicate any other than the
       square root, a corresponding figure is placed over the
       sign; thus [cuberoot]a, indicates the third or cube root
       of a.
    {Radical stress} (Elocution), force of utterance falling on
       the initial part of a syllable or sound.
    {Radical vessels} (Anat.), minute vessels which originate in
       the substance of the tissues.
    Syn: Primitive; original; natural; underived; fundamental;
    Usage: {Radical}, {Entire}. These words are frequently
           employed as interchangeable in describing some marked
           alternation in the condition of things. There is,
           however, an obvious difference between them. A radical
           cure, reform, etc., is one which goes to the root of
           the thing in question; and it is entire, in the sense
           that, by affecting the root, it affects in a
           appropriate degree the entire body nourished by the
           root; but it may not be entire in the sense of making
           a change complete in its nature, as well as in its
           extent. Hence, we speak of a radical change; a radical
           improvement; radical differences of opinion; while an
           entire change, an entire improvement, an entire
           difference of opinion, might indicate more than was
           actually intended. A certain change may be both
           radical and entire, in every sense.
  2. \Rad"i*cal\, n.
    1. (Philol.)
       (a) A primitive word; a radix, root, or simple, underived,
           uncompounded word; an etymon.
       (b) A primitive letter; a letter that belongs to the
                 The words we at present make use of, and
                 understand only by common agreement, assume a
                 new air and life in the understanding, when you
                 trace them to their radicals, where you find
                 every word strongly stamped with nature; full of
                 energy, meaning, character, painting, and
                 poetry.                           --Cleland.
    2. (Politics) One who advocates radical changes in government
       or social institutions, especially such changes as are
       intended to level class inequalities; -- opposed to
             In politics they [the Independents] were, to use
             phrase of their own time. ``Root-and-Branch men,''
             or, to use the kindred phrase of our own, Radicals.
    3. (Chem.)
       (a) A characteristic, essential, and fundamental
           constituent of any compound; hence, sometimes, an
                 As a general rule, the metallic atoms are basic
                 radicals, while the nonmetallic atoms are acid
                 radicals.                         --J. P. Cooke.
       (b) 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.
    4. (Alg.) A radical quantity. See under {Radical}, a.
             An indicated root of a perfect power of the degree
             indicated is not a radical but a rational quantity
             under a radical form.                 --Davies &
                                                   Peck (Math.
    5. (Anat.) A radical vessel. See under {Radical}, a.
Biology Dictionary
  1. Of leaves, clustered at the base of the stem.
  2. An atom or or electrically neutral molecule that has one or more unpaired electrons in its outer orbital. Free radicals are unstable and react quickly with other atoms and molecules; because of this, they can cause damage to living tissues.