radical

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radical

 [rad´ĭ-kal]
1. thorough or sweeping; directed to the cause or root of a morbid process.
2. a group of atoms that enters into and goes out of chemical combination without change and that forms one of the fundamental constituents of a molecule.
color radical chromophore.
free radical a radical that carries an unpaired electron; such radicals are extremely reactive, with a very short half-life.
oxygen radical a toxic metabolite of oxygen, such as superoxide or singlet oxygen, capable of damaging microorganisms and normal tissues.

rad·i·cal

(rad'i-kăl), Do not confuse this word with radicle.
1. In chemistry, a group of elements or atoms usually passing intact from one compound to another, but usually incapable of prolonged existence in a free state (for example, methyl, CH3); in chemical formulas, a radical is often distinguished by being enclosed in parentheses or brackets.
2. Thorough or extensive; relating or directed to the extirpation of the root or cause of a morbid process; for example, a radical operation.
3. Denoting treatment by extreme, drastic, or innovative, as opposed to conservative, measures.
4. Synonym(s): free radical
5. A functional group in a molecule or molecular entity.
[L. radix (radic-), root]

radical

/rad·i·cal/ (rad´ĭ-k'l)
1. directed to the root or cause; designed to eliminate all possible extensions of a morbid process.
2. a group of atoms that enters and goes out of chemical combination without change.

free radical  a radical that carries an unpaired electron; such radicals are extremely reactive, with a very short half-life.

radical

(răd′ĭ-kəl)
adj.
1. Departing markedly from the usual or customary; extreme or drastic: a radical change in diet.
2. Medicine Relating to or being surgery that is extreme or drastic in an effort to eradicate all existing or potential disease: radical hysterectomy.
3. Botany
a. Of, relating to, or arising from a root: radical hairs.
b. Arising from the base of a stem or from a below-ground stem or rhizome: radical leaves.

rad′i·cal·ly adv.
rad′i·cal·ness n.

radical

[rad′ikəl]
Etymology: L, radix, root
1 n, an atom or group of atoms that contains an unpaired electron. A radical does not exist freely in nature except for O2, NO, and NO2.
2 adj, pertaining to drastic therapy, such as the surgical removal of an organ, limb, or other part of the body.

rad·i·cal

(rad'i-kăl)
1. chemistry A group of elements or atoms usually passing intact from one compound to another, but usually incapable of prolonged existence in a free state (e.g., methyl, CH3); in chemical formulas, a radical is often distinguished by being enclosed in parentheses or brackets.
2. Directed to the extirpation of the root or cause of a morbid process, e.g., a radical operation.
3. Denoting treatment by extreme, drastic, or innovative, as opposed to conservative, measures.
4. Synonym(s): free radical.
[L. radix (radic-), root]

radical

(of plants) arising from the root or crown.

rad·i·cal

(rad'i-kăl)
1. In chemistry, a group of elements or atoms usually passing intact from one compound to another, but usually incapable of prolonged existence in a free state (e.g., methyl, CH3).
2. Thorough or extensive; relating or directed to the extirpation of the root or cause of a morbid process.
3. Denoting treatment by extreme, drastic, or innovative, as opposed to conservative, measures.
[L. radix (radic-), root]

radical,

n 1. a group of atoms that acts together and forms a component of a compound. The group tends to remain bound together when a chemical reaction removes it from one compound and attaches it to another compound. A radical does not exist freely in nature.
adj 2. a drastic measure to cure or prevent the spread of a serious disease, such as the surgical removal of an organ, limb, or other body part.

radical

1. directed to the cause; going to the root or source of a morbid process.
2. a group of atoms that enters into and goes out of chemical combination without change and that forms one of the fundamental constituents of a molecule.

free radical
a radical, extremely reactive, and having a very short half-life (10−5 s or less in an aqueous solution), which carries an unpaired electron.