radical
['rædɪkl.]
n. 激, 词根, 础, 根, 根

a. 激, 根, , 根

[] 根; 团;

[医] 根, , 团



radical
[ noun ]

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

<noun.substance>

2. 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

<noun.substance>
in the body free radicals are high-energy particles that ricochet wildly and damage cells

3. a person who has radical ideas or opinions

<noun.person>

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

<noun.quantity>

5. a character conveying the lexical meaning of a logogram

<noun.communication>

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

<noun.communication>
thematic vowels are part of the stem

[ adj ]

1. of or relating to or constituting a linguistic root

<adj.pert>
a radical verb form

2. 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

<adj.all>
basal placentation
radical leaves

3. (used of opinions and actions) far beyond the norm

<adj.all>
extremist political views
radical opinions on education
an ultra conservative

4. markedly new or introducing radical change

<adj.all>
a revolutionary discovery
radical political views

5. arising from or going to the root or source

<adj.all>
a radical flaw in the plan

Radical \Rad"i*cal\ (r[a^]d"[i^]*kal), 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
root.

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;
entire.

Usage: {Radical}, {Entire}. These words are frequently
employed as interchangeable in describing some marked
alteration 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 an
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.


Radical \Rad"i*cal\ (r[a^]d"[i^]*kal), 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
radix.

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
conservative.

In politics they [the Independents] were, to use the
phrase of their own time, ``Root-and-Branch men,''
or, to use the kindred phrase of our own, Radicals.
--Macaulay.

3. (Chem.)
(a) A characteristic, essential, and fundamental
constituent of any compound; hence, sometimes, an
atom.

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.
{Residue}.

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.
Dict.)

5. (Anat.) A radical vessel. See under {Radical}, a.


Residue \Res"i*due\ (r?z"?-d?), n. [F. r['e]sidu, L. residuum,
fr. residuus that is left behind, remaining, fr. residere to
remain behind. See {Reside}, and cf. {Residuum}.]
1. That which remains after a part is taken, separated,
removed, or designated; remnant; remainder.

The residue of them will I deliver to the sword.
--Jer. xv. 9.

If church power had then prevailed over its victims,
not a residue of English liberty would have been
saved. --I. Taylor.

2. (Law) That part of a testeator's estate wwhich is not
disposed of in his will by particular and special legacies
and devises, and which remains after payment of debts and
legacies.

3. (Chem.) That which remains of a molecule after the removal
of a portion of its constituents; hence, an atom or group
regarded as a portion of a molecule; a {moiety} or
{group}; -- used as nearly equivalent to {radical}, but in
a more general sense.
[1913 Webster +PJC]

Note: The term radical is sometimes restricted to groups
containing carbon, the term residue and {moiety} being
applied to the others.

4. (Theory of Numbers) Any positive or negative number that
differs from a given number by a multiple of a given
modulus; thus, if 7 is the modulus, and 9 the given
number, the numbers -5, 2, 16, 23, etc., are residues.

Syn: Rest; remainder; remnant; balance; residuum; remains;
leavings; relics.