radio-

a combining form with the meanings “dealing with radiant energy” (radiometer), “employing or dealing with radio waves” (radioacoustics; radiolocation; radiotelephone), “emitting rays as a result of the breakup of atomic nuclei” (radioactive; radiocarbon), “characterized by, employing or dealing with such rays” (radiography; radiopaque; radiotherapy).

Origin

< French, combining form representing Latin radius beam, ray, radius

British Dictionary definitions for radio-

radio-

combining form

denoting radio, broadcasting, or radio frequency: radiogram

indicating radioactivity or radiation: radiochemistry, radiolucent

indicating a radioactive isotope or substance: radioactinium, radiothorium, radioelement

Word Origin

from French, from Latin radius ray; see radius

Word Origin and History for radio-

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- in Medicine

radio- or radi-
pref.

Radiation; radiant energy: radiometer.
Radioactive: radiochemistry.
Radius: radiobicipital.