radicalとは 意味・読み方・使い方

発音

• IPA^(key): /ˈɹædɪkəl/
• Homophone: radicle

形容詞

radical (comparative more radical, superlative most radical)

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

   His beliefs are radical.

2. (botany, not comparable) Pertaining to a root (of a plant).
3. Pertaining to the basic or intrinsic nature of something.

   Synonym: fundamental

   Antonyms: ignorable, trivial

   • 1790 November, Edmund Burke, Reflections on the Revolution in France, and on the Proceedings in Certain Societies in London Relative to that Event. […], London: […] J[ames] Dodsley, […], →OCLC:

     The most determined exertions of that authority, against them, only showed their radical independence.

4. Thoroughgoing; far-reaching.

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

   • 2012 January, Donald Worster, “A Drier and Hotter Future”, in American Scientist‎^[1], volume 100, number 1, archived from the original on 26 January 2012, page 70:

     Phoenix and Lubbock are both caught in severe drought, and it is going to get much worse. We may see many such [dust] storms in the decades ahead, along with species extinctions, radical disturbance of ecosystems, and intensified social conflict over land and water. Welcome to the Anthropocene, the epoch when humans have become a major geological and climatic force.

5. (lexicography, not comparable) Of or pertaining to the root of a word.
6. (phonology, phonetics, not comparable, of a sound) Produced using the root of the tongue.

   Coordinate terms: coronal, dorsal, labial, laryngeal

7. (chemistry, not comparable) Involving free radicals.
8. (mathematics) Relating to a radix or mathematical root.

   a radical quantity; a radical sign

9. (slang, 1980s & 1990s) Excellent; awesome.

   That was a radical jump!

同意語

• (linguistics, in reference to words): primitive

反意語

• (linguistics, in reference to words): derivative, derived

派生語

関連する語

名詞

radical (複数形 radicals)

1. (historical, 19th-century Britain) A member of the most progressive wing of the Liberal Party; someone favouring social reform (but generally stopping short of socialism).
2. (historical, early 20th-century France) A member of an influential, centrist political party favouring moderate social reform, a republican constitution, and secular politics.
3. A person with radical opinions.
4. (arithmetic) A root (of a number または quantity).
6. (linguistics) In logographic writing systems such as the Chinese writing system, the portion of a character (if any) that provides an indication of its meaning, as opposed to phonetic.
7. (linguistics) In Celtic languages, refers to the basic, underlying form of an initial consonant which can be further mutated under the Celtic initial consonant mutations.
8. (linguistics) In Semitic languages, any one of the set of consonants (typically three) that make up a root.
9. (chemistry) A group of atoms, joined by covalent bonds, that take part in reactions as a single unit.
10. (organic chemistry) A free radical.
11. (algebra, commutative algebra, ring theory, of an ideal) Given an ideal I in a commutative ring R, another ideal, denoted Rad(I) or ${\displaystyle {\sqrt {I}}}$, such that an element x ∈ R is in Rad(I) if, for some positive integer n, xⁿ ∈ I; equivalently, the intersection of all prime ideals containing I.
12. (algebra, ring theory, of a ring) Given a ring R, an ideal containing elements of R that share a property considered, in some sense, "not good".
13. (algebra, ring theory, of a module) The intersection of maximal submodules of a given module.
14. (number theory) The product of the distinct prime factors of a given positive integer.

派生語

関連する語

• nilradical

参照

• “radical”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.
• “radical”, in The Century Dictionary […], New York, N.Y.: The Century Co., 1911, →OCLC.
• "radical" in Raymond Williams, Keywords (revised), 1983, Fontana Press, page 251.

Further reading

• Radical on Wikipedia.
• Radical of an ideal on Wikipedia.
• Radical of a ring on Wikipedia.
• Radical of a module on Wikipedia.
• Radical of an integer on Wikipedia.
• Radical of an ideal on Encyclopedia of Mathematics
• Ideal Radical on Wolfram MathWorld

アナグラム

• aldaric, cardial