English Words Starting With R

• radiocommunication

  nounC2
  /ˌreɪdiəʊkəˌmjuːnɪˈkeɪʃ(ə)n/The transmission of signals or information via radio waves.
• radiodiagnosis

  nounC1/C2
  /ˌreɪ.di.əʊ.daɪ.əɡˈnəʊ.sɪs/The use of X-rays and other forms of radiation to diagnose diseases and conditions.
• radioelement

  nounC2
  /ˌreɪdiəʊˈelɪmənt/A chemical element whose isotopes are all radioactive.
• radiofrequency

  nounC1
  /ˌreɪdiəʊˈfriːkwənsi/An electromagnetic wave frequency lying within the radio spectrum, typically between 3 kHz and 300 GHz.
• radiogoniometer

  nounVery Low / Technical Obsolete
  /ˌreɪdiəʊˌɡəʊniˈɒmɪtə/An instrument used in radio navigation and direction finding to measure the angle of arrival of incoming radio waves, typically to determine the direction to a radio transmitter.
• radiogram

  noununcommon
  /ˈreɪ.di.ə.ɡræm/A device that combines a radio and a gramophone for receiving broadcasts and playing vinyl records.
• radiograph

  nounverb-transitiveC2
  /ˈreɪ.di.əʊ.ɡrɑːf/An image produced on a sensitive surface by X-rays or other radiation, used to examine the internal structure of objects, especially the human body.
• radiography

  nounLow
  /ˌreɪdiˈɒɡrəfi/The process of producing images of the internal structures of the body, especially for medical diagnosis, using X-rays or gamma rays.
• radioimmunoassay

  nounLow (C2/Technical)
  /ˌreɪdɪəʊˌɪmjʊnəʊˈæseɪ/A highly sensitive laboratory technique that uses radioactive isotopes and antibodies to measure tiny amounts of specific substances, like hormones or drugs, in biological samples.
• radioimmunology

  nounC2 (Very low frequency, specialist vocabulary)
  /ˌreɪdiəʊˌɪmjʊˈnɒlədʒi/The study of immune responses using radioactive substances to label and trace antigens and antibodies.
• radioiodine

  nounC2
  /ˌreɪdiəʊˈaɪədiːn/A radioactive isotope of iodine, especially iodine-131.
• radioiron

  nounVery Low/Very Technical
  /ˌreɪ.di.əʊ.ˈaɪ.ən/A radioactive isotope of iron, typically iron-59, used as a tracer in biological and industrial research.
• radioisotope

  nounC2
  /ˌreɪ.di.əʊˈaɪ.sə.təʊp/A radioactive isotope of a chemical element, with an unstable nucleus that decays, emitting radiation.
• radiolabel

  verb-transitiveC2 - Very low frequency, specialized technical term.
  /ˈreɪ.di.əʊˌleɪ.bəl/To label or tag a molecule, substance, or biological entity with a radioactive isotope, allowing it to be traced, detected, or quantified in chemical, biological, or medical research.
• radioland

  nounRare / Historical
  /ˈreɪ.di.əʊ.lænd/An imagined collective space or community of radio listeners; the audience of radio broadcasting.
• radiolarian

  nounRare (C2+)
  /ˌreɪdɪə(ʊ)ˈleərɪən/A microscopic marine protozoan with a delicate, symmetrical silica skeleton.
• radiolocation

  nounC2
  /ˌreɪ.di.əʊ.ləʊˈkeɪ.ʃən/The process of determining the position of an object by using radio waves.
• radiolocator

  nounVery Low (specialist/technical)
  /ˌreɪ.di.əʊ.ləʊˈkeɪ.tə(r)/A device or system for determining the precise geographical location of an object using radio signals.
• radiology

  nounC1/C2
  /ˌreɪ.diˈɒl.ə.dʒi/The branch of medicine that uses imaging technologies (like X-rays, CT scans, MRI) to diagnose and sometimes treat diseases.
• radioluminescence

  nounVery Low (Scientific/Technical)
  /ˌreɪ.di.əʊˌluː.mɪˈnes.əns/The emission of light by a material as a result of absorbing radiation, typically from a radioactive source.

Showing 281–300 of 5802 words.