<B>radiopaque, </B>adjective.<DL COMPACT><DD> not transparent to X rays or other radioactive substances. <BR> <I>Ex. The velocity of blood flow--is easily determined by injecting a radiopaque substance into the bloodstream and measuring the rate of travel of its shadow on a film (Scientific American).</I> </DL>
<A NAME="radiophare">
<B>radiophare, </B>noun.<DL COMPACT><DD> a radio station for determining the position of ships at sea. </DL>
<A NAME="radiopharmaceutical">
<B>radiopharmaceutical, </B>noun.<DL COMPACT><DD> a radioactive drug used especially for the treatment of tumors and for diagnostic purposes. </DL>
<B>radiophonic, </B>adjective.<DL COMPACT><DD> having to do with the radiophone or radiophony. adv. <B>radiophonically.</B> </DL>
<A NAME="radiophonograph">
<B>radio phonograph,</B><DL COMPACT><DD> an appliance including both a radio receiver and a phonograph. </DL>
<A NAME="radiophony">
<B>radiophony, </B>noun.<DL COMPACT><DD> the science or process of producing sound by the action of radiant energy. </DL>
<A NAME="radiophosphorus">
<B>radiophosphorus, </B>noun.<DL COMPACT><DD> a radioisotope of phosphorus, used in the treatment of leukemia and other diseases of the blood. </DL>
<A NAME="radiophoto">
<B>radiophoto, </B>noun, pl. <B>-tos,</B> verb.<DL COMPACT><DD><I>noun </I> <B>1. </B><B>=radiophotograph.</B> <DD><B> 2. </B><B>=radiophotography.</B> <DD><I>v.t. </I> to send a radiophoto of. <BR> <I>Ex. I am frantic to get my film to Saigon, where it can be radiophotoed to New York (New York Times Magazine).</I> </DL>
<A NAME="radiophotograph">
<B>radiophotograph, </B>noun.<DL COMPACT><DD> a photograph transmitted by radio. </DL>
<A NAME="radiophotographic">
<B>radiophotographic, </B>adjective.<DL COMPACT><DD> of or by radiophotography. </DL>
<A NAME="radiophotography">
<B>radiophotography, </B>noun.<DL COMPACT><DD> the transmission of a photograph by radio. </DL>
<A NAME="radiophysics">
<B>radiophysics, </B>noun.<DL COMPACT><DD> the branch of physics dealing with radioactive substances. </DL>
<A NAME="radiopill">
<B>radio pill,</B><DL COMPACT><DD> a miniaturized radio transmitter enclosed in a plastic capsule that can be swallowed and used to transmit signals on gastrointestinal and other conditions as it passes through the body. </DL>
<A NAME="radioprotection">
<B>radioprotection, </B>noun.<DL COMPACT><DD> protection against the effects of radiation. </DL>
<A NAME="radioprotective">
<B>radioprotective, </B>adjective.<DL COMPACT><DD> providing radioprotection. <BR> <I>Ex. Dopamine, an intermediate hormone formed by the adrenal glands in the synthesis of norepinephrine, is a good radioprotective agent (J. Richard Thomson).</I> </DL>
<A NAME="radioprotector">
<B>radioprotector, </B>noun.<DL COMPACT><DD> a radioprotective drug or agent. </DL>
<A NAME="radiorange">
<B>radio range,</B><DL COMPACT><DD><B> 1. </B>the reach of a radio beam or beams emitted by a radio beacon. <DD><B> 2. </B>the station emitting such beams; radio beacon. </DL>
<A NAME="radiorangebeacon">
<B>radio range beacon,</B> <B>=radio beacon.</B></DL>
<A NAME="radioscope">
<B>radioscope, </B>noun.<DL COMPACT><DD><B> 1. </B>an instrument for studying and applying X rays. <DD><B> 2. </B>a form of spinthariscope. </DL>
<A NAME="radioscopic">
<B>radioscopic, </B>adjective.<DL COMPACT><DD> of or having to do with the radioscope or radioscopy. </DL>
<B>radioscopy, </B>noun.<DL COMPACT><DD> the examination of opaque objects by means of X rays or other radioactive substances. </DL>
<A NAME="radiosensitive">
<B>radiosensitive, </B>adjective.<DL COMPACT><DD> sensitive to X rays or other radioactivity. </DL>
<A NAME="radiosensitivity">
<B>radiosensitivity, </B>noun.<DL COMPACT><DD> the sensitivity of tissues, organisms, or other objects, to X rays or other radioactivity. <BR> <I>Ex. The increased radiosensitivity of a child's body must be considered in contrast to that of the adult (Bulletin of Atomic Scientists).</I> </DL>
<A NAME="radiosensitizer">
<B>radiosensitizer, </B>noun.<DL COMPACT><DD> a chemical substance that sensitizes cells to the effects of X rays or other radioactivity. <BR> <I>Ex. Important work is under way into radiosensitizers--drugs that enhance the effectiveness of radiation therapy (Maclean's).</I> </DL>
<A NAME="radiosodium">
<B>radiosodium, </B>noun.<DL COMPACT><DD> a radioisotope of sodium, used in studying blood circulation and water metabolism, and in the treatment of kidney and other diseases. </DL>
<A NAME="radiosonde">
<B>radiosonde, </B>noun.<DL COMPACT><DD> an instrument carried into the stratosphere by means of a balloon, from which it descends by parachute, automatically reporting data on atmospheric temperature, pressure, and humidity to the ground by means of a small radio transmitter. </DL>
<A NAME="radiosource">
<B>radio source,</B> <B>=radio star.</B></DL>
<A NAME="radiospectrum">
<B>radio spectrum,</B><DL COMPACT><DD> the entire range of radio waves, from 3 centimeters to 30,000 meters. </DL>
<A NAME="radiostar">
<B>radio star,</B><DL COMPACT><DD> a powerful mass of energy in space that emits radio waves instead of light waves. Radio stars are studied by radio astronomers. <BR> <I>Ex. There seem to be a great number of these radio stars: more than 200 are now known, and it is likely that vastly greater numbers will be found as radio telescopes are improved (A. C. B. Lovell).</I> </DL>
<A NAME="radiostation">
<B>radio station,</B><DL COMPACT><DD><B> 1. </B>an installation consisting of radio-transmitting devices, broadcasting studios, and all other equipment necessary for radiobroadcasting. <DD><B> 2. </B>an organization or department in the business of commercial broadcasting. </DL>
<A NAME="radiosterilization">
<B>radiosterilization, </B>noun.<DL COMPACT><DD> sterilization of medical instruments, apparatus, and the like, by means of radioactive rays. </DL>
<A NAME="radiosterilize">
<B>radiosterilize, </B>transitive verb, <B>-lized,</B> <B>-lizing.</B><DL COMPACT><DD> to sterilize by subjecting to radioactive rays. </DL>
<A NAME="radiostrontium">
<B>radiostrontium, </B>noun.<DL COMPACT><DD> a radioisotope of strontium that forms part of the fallout of a hydrogen bomb explosion; strontium 90. <BR> <I>Ex. Radiostrontium ... is the principal radioactive hazard to the farms and forests if atomic war comes (Science News Letter).</I> </DL>
<A NAME="radiostudio">
<B>radio studio,</B><DL COMPACT><DD> a room, usually with special acoustic properties, from which a radiobroadcast can be made. </DL>
<A NAME="radiosurgery">
<B>radiosurgery, </B>noun.<DL COMPACT><DD> surgery involving the use of radioactive materials. <BR> <I>Ex. Radiosurgery on the brain without opening the skull was reported by Swedish and American neurosurgeons (Science News Letter).</I> </DL>
<B>radiotelegram, </B>noun.<DL COMPACT><DD> a message transmitted by radiotelegraphy; radiogram. </DL>
<A NAME="radiotelegraph">
<B>radiotelegraph, </B>noun, verb.<DL COMPACT><DD><I>noun </I> <B>1. </B>a telegraph transmitting by radio waves instead of by electric wires. <DD><B> 2. </B><B>=radiotelegraphy.</B> <DD><I>v.t., v.i. </I> to telegraph by radio. </DL>
<A NAME="radiotelegraphic">
<B>radiotelegraphic, </B>adjective.<DL COMPACT><DD> of or having to do with radiotelegraphy. </DL>
<A NAME="radiotelegraphy">
<B>radiotelegraphy, </B>noun.<DL COMPACT><DD> system of telegraphing by radio; wireless telegraphy. </DL>
<A NAME="radiotelemeter">
<B>radiotelemeter, </B>noun.<DL COMPACT><DD> a device or apparatus for taking measurements by radiotelemetry. </DL>
<A NAME="radiotelemetric">
<B>radiotelemetric, </B>adjective.<DL COMPACT><DD> having to do with radiotelemetry. </DL>
<A NAME="radiotelemetry">
<B>radiotelemetry, </B>noun.<DL COMPACT><DD> the automatic taking of measurements at distant or inaccessible points, as within a nuclear reactor, and the transmission of the data to a receiving point, specifically by means of radio. <BR> <I>Ex. Radiotelemetry, permitting study of heart function at any moment of exertion (San Francisco Chronicle).</I> </DL>
<A NAME="radiotelephone">
<B>radiotelephone, </B>noun, verb, <B>-phoned,</B> <B>-phoning.</B><DL COMPACT><DD><I>noun </I> a radio transmitter using voice communication. <DD><I>v.t., v.i. </I> to telephone by radio. <BR> <I>Ex. [He] radiotelephoned to the White House a request to report to the nation on the crisis (Time).</I> </DL>
<A NAME="radiotelephonic">
<B>radiotelephonic, </B>adjective.<DL COMPACT><DD> of or having to do with a radiotelephone. </DL>
<A NAME="radiotelephony">
<B>radiotelephony, </B>noun.<DL COMPACT><DD> radio communication by means of voice signals. </DL>
<A NAME="radiotelescope">
<B>radio telescope,</B><DL COMPACT><DD> a device used in radio astronomy for detecting and recording radio waves coming from stars and other objects in outer space. It consists of a radio receiver with an antenna fixed on a wide bowl-shaped reflector which collects and focuses the waves. <BR> <I>Ex. A great advantage of the radio telescope is that it can "see" much farther than optical instruments (Scientific American).</I> </DL>
<A NAME="radiotherapeutic">
<B>radiotherapeutic, </B>adjective.<DL COMPACT><DD> of or having to do with the treatment of disease by means of X rays or radioactive agencies. </DL>
<A NAME="radiotherapeutics">
<B>radiotherapeutics, </B>noun.<DL COMPACT><DD> the branch of therapeutics that deals with the use of X rays or radioactive substances such as radium in the treatment of disease. </DL>
<A NAME="radiotherapist">
<B>radiotherapist, </B>noun.<DL COMPACT><DD> an expert in radiotherapy. <BR> <I>Ex. By dividing and spreading the dose radiotherapists can treat cancerous tissue with thousands of rads without excessive damage to the patient (Scientific American).</I> </DL>
<A NAME="radiotherapy">
<B>radiotherapy, </B>noun.<DL COMPACT><DD> the treatment of disease by means of X rays or radioactive agencies. <BR> <I>Ex. ... kilocurie sources of radiocaesium for use in radiotherapy (Bulletin of Atomic Scientists).</I> </DL>
<A NAME="radiothermy">
<B>radiothermy, </B>noun.<DL COMPACT><DD> diathermy by a short-wave radio apparatus. </DL>
<A NAME="radiothorium">
<B>radiothorium, </B>noun.<DL COMPACT><DD> a radioactive isotope of thorium, having a mass number of 228. It is a disintegration product of mesothorium II. </DL>
