- radio-
[radio- 词源字典] - word-forming element meaning 1. "ray, ray-like" (see radius); 2. "radial, radially" (see radial (adj.)); 3. "by means of radiant energy" (see radiate (v.)); 4. "radioactive" (see radioactive); 5. "by radio" (see radio (n.)).[radio- etymology, radio- origin, 英语词源]
- radio-carbon (n.)
- "Carbon-14," 1940, from radio-, comb. form of radioactive, + carbon. Radio-carbon dating is attested from 1949.
- radio-telephone (n.)
- 1900, from radio (n.) + telephone (n.).
- radioactive (adj.)
- 1898, from French radio-actif, coined by Pierre and Marie Curie from radio-, comb. form of Latin radius (see radiation) + actif "active" (see active).
- radioactivity (n.)
- 1899, from French radioactivité, coined 1898 by the Curies; see radioactive.
- radiocast (n.)
- 1924, from radio (n.) + ending from broadcast.
- radiography (n.)
- 1896, from radiograph (1880), originally a device to measure sunshine; from radio-, comb. form of radiation, + -graph. As a type of image-making device, from 1896.
- radioisotope (n.)
- 1946, from radio-, comb. form of radiation, + isotope.
- radiolarian (n.)
- 1862, from Radiolaria, Modern Latin classification name, from Latin radiolus, diminutive of radius (q.v.).
- radiology (n.)
- 1900, "medical use of X-rays," later extended to "scientific study of radiation," from radio-, comb. form of radiation, + Greek-based scientific suffix -ology. Related: Radiological.
- radiometric (adj.)
- 1877, from radiometer "instrument to transform radiant energy into mechanical work" (1875), radiometry, from radio-, here indicating "radiant energy," + -metric. Radiometric dating attested from 1906.
- radioscopy (n.)
- 1896, from radio- + -scopy.
- radiotherapy (n.)
- 1903, from radio- + therapy.
- radish (n.)
- late Old English rædic "radish," from Latin radicem (nominative radix) "root, radish," from PIE root *wrad- "twig, root" (cognates: Greek rhiza, Lesbian brisda "root;" Greek hradamnos "branch;" Gothic waurts, Old English wyrt; Welsh gwridd, Old Irish fren "root"). Spelling perhaps influenced by Old French radise, variant of radice, from Vulgar Latin *radicina, from radicem.
- radium (n.)
- radioactive metallic element, 1899, from French radium, named 1898 after identification by Marie Curie and her husband, formed in Modern Latin from Latin radius "ray" (see radius). So called for its power of emitting energy in the form of rays.
- radius (n.)
- 1590s, "cross-shaft," from Latin radius "staff, stake, rod; spoke of a wheel; ray of light, beam of light; radius of a circle," of unknown origin. Perhaps related to radix "root," but Tucker suggests connection to Sanskrit vardhate "rises, makes grow," via root *neredh- "rise, out, extend forth;" or else Greek ardis "sharp point."
The geometric sense first recorded 1610s. Plural is radii. Meaning "circular area of defined distance around some place" is attested from 1953. Meaning "shorter bone of the forearm" is from 1610s in English (the Latin word had been used thus by the Romans). - Radnor
- place in eastern Wales, the name is Old English, literally "at the red bank," from Old English read (dative singular readan; see red (n.1) + ofer "bank, slope."
- radon (n.)
- heaviest gaseous element, 1918, from German Radon, from radium (q.v.) + -on suffix of inert gases. The element was identified in radioactive decay of radium. Alternative name niton (from Latin nitens "shining") gained currency in France and Germany.
- radula (n.)
- surgical instrument, 1753, from Latin radula "scraper, scraping iron," from radere "to scrape" (see raze). Related: Radular.
- raffia (n.)
- fiber-yielding tree of Madagascar, 1729, rofia, from Malagasy rafia. Modern form is attested from 1882; also raphia (1866).
