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
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.
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
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.