radiance (n.)youdaoicibaDictYouDict[radiance 词源字典]
c. 1600, "brilliant light," from radiant or else from Medieval Latin radiantia "brightness," from radiare "to beam, shine" (see radiation). Figurative use from 1761. Related: Radiancy.[radiance etymology, radiance origin, 英语词源]
radiant (adj.)youdaoicibaDictYouDict
mid-15c., from Middle French radiant and directly from Latin radiantem (nominative radians) "beaming, shining," present participle of radiare "to beam, shine" (see radiation). Of beauty, etc., first attested c. 1500. Related: Radiantly.
radiant (n.)youdaoicibaDictYouDict
"point or object from which light radiates," 1727; see radiant (adj.). In astronomy, of meteor showers, from 1864.
radiate (v.)youdaoicibaDictYouDict
1610s, "spread in all directions from a point," from Latin radiatus, past participle of radiare "to beam, shine, gleam; make beaming" (see radiation). Meaning "be radiant, give off rays (of light or heat)" is from 1704. Related: Radiated; radiates; radiating.
radiate (adj.)youdaoicibaDictYouDict
"having rays, furnished with rays, shining," 1660s, from Latin radiatus (see radiate (v.)).
radiation (n.)youdaoicibaDictYouDict
mid-15c., "act or process of radiating," from Middle French radiation and directly from Latin radiationem (nominative radiatio) "a shining, radiation," noun of action from past participle stem of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius). Meaning "rays or beams emitted" is from 1560s. Meaning "divergence from a center" is 1650s.
radiative (adj.)youdaoicibaDictYouDict
"having a tendency to radiate," 1820, from radiate (v.) + -ive. Related: Radiativity.
radiator (n.)youdaoicibaDictYouDict
1836, "any thing that radiates," agent noun in Latin form from radiate. Meaning "heater" is from 1851; sense of "cooling device in internal combustion engine" is 1900.
radical (adj.)youdaoicibaDictYouDict
late 14c., in a medieval philosophical sense, from Late Latin radicalis "of or having roots," from Latin radix (genitive radicis) "root" (see radish). Meaning "going to the origin, essential" is from 1650s. Radical sign in mathematics is from 1680s.

Political sense of "reformist" (via notion of "change from the roots") is first recorded 1802 (n.), 1817 (adj.), of the extreme section of the British Liberal party (radical reform had been a current phrase since 1786); meaning "unconventional" is from 1921. U.S. youth slang use is from 1983, from 1970s surfer slang meaning "at the limits of control." Radical chic is attested from 1970; popularized, if not coined, by Tom Wolfe. Radical empiricism coined 1897 by William James (see empiricism).
radical (n.)youdaoicibaDictYouDict
1630s, "root part of a word, from radical (adj.) Political sense from 1802; chemical sense from 1816.
radicalism (n.)youdaoicibaDictYouDict
1819 in the political sense, from radical (adj.) + -ism.
radicality (n.)youdaoicibaDictYouDict
1640s, from radical (adj.) + -ity.
radicalize (v.)youdaoicibaDictYouDict
1820, from radical (adj.) + -ize. Related: Radicalized; radicalizing.
radically (adv.)youdaoicibaDictYouDict
c. 1600, "thoroughly;" 1620s with reference to roots and origins, from radical (adj.) + -ly (2).
radicand (n.)youdaoicibaDictYouDict
the number under a radical sign, from Latin radicandus, gerundive of radicare (see radicant).
radicant (adj.)youdaoicibaDictYouDict
"bringing forth roots," 1735, from Latin radicantem (nominative radicans), present participle of radicare, from radix "root" (see radish).
radicle (n.)youdaoicibaDictYouDict
1670s, in botany, from Latin radicula, diminutive of radix (see radish).
radicular (adj.)youdaoicibaDictYouDict
"pertaining to roots," 1830, from Modern Latin radicula, diminutive of Latin radix (see radish) + -ar.
radio (n.)youdaoicibaDictYouDict
"wireless transmission of voice signals with radio waves," 1907, abstracted from earlier combinations such as radio-receiver (1903), radiophone (1881), radio-telegraphy (1898), from radio- as a comb. form of Latin radius "beam." Use for "radio receiver" is first attested 1913; sense of "sound broadcasting as a medium" is from 1913.
It is not a dream, but a probability that the radio will demolish blocs, cut the strings of red tape, actuate the voice "back home," dismantle politics and entrench the nation's executive in a position of power unlike that within the grasp of any executive in the world's history. ["The Reading Eagle," Reading, Pa., U.S.A., March 16, 1924]
In U.S., stations were broadcasting news and music by late 1920, but the new medium caught on nationwide as a fad in the winter of 1921-22; as late as July 1921 the "New York Times" had called it wireless telephony, and wireless remained more widespread until World War II, when military preference for radio turned the tables. As an adjective by 1912, "by radio transmission;" meaning "controlled by radio" from 1974. Radio _______ "radio station or service from _______" is recorded from 1920. A radio shack (1946) was a small building housing radio equipment.
radio (v.)youdaoicibaDictYouDict
1916, from radio (n.). Related: Radioed; radioing.