radioisotope

noun

ra·​dio·​iso·​tope ˌrā-dē-ō-ˈī-sə-ˌtōp 

: a radioactive isotope

radioisotopic

ˌrā-dē-ō-ˌī-sə-ˈtä-pik 

-ˈtō-

adjective

radioisotopically

ˌrā-dē-ō-ˌī-sə-ˈtä-pi-k(ə-)lē 

adverb

Examples of radioisotope in a Sentence

Recent Examples on the Web

Testing heat without sunlight Zeno’s payload centers on a five-watt radioisotope heater unit containing americium-241. — Aamir Khollam, Interesting Engineering, 20 Aug. 2026

For example, unlike plutonium, which has been used in nuclear batteries deployed in Mars rovers and deep space probes, tritium is considered a relatively low-risk radioisotope. — Tereza Pultarova, IEEE Spectrum, 10 Aug. 2026

Voyager 2 and its twin launched in 1977, called Voyager 1, rely on a form of nuclear battery known as a radioisotope thermoelectric generator that uses the heat produced by the decay of plutonium. — Elizabeth Howell, Space.com, 7 Aug. 2026

Both Voyager probes run on radioisotope thermoelectric generators, or devices that convert the heat provided by decaying plutonium into electricity. — Ashley Strickland, CNN Money, 6 Aug. 2026

Word History

Etymology

International Scientific Vocabulary

First Known Use

1938, in the meaning defined above

Rhymes for radioisotope

• antelope
• bronchoscope
• cantaloupe
• cystoscope
• endoscope
• envelope
• epitope
• gyroscope
• horoscope
• isotope
• microscope
• misanthrope

Kids Definition

radioisotope

noun

ra·​dio·​iso·​tope ˌrād-ē-ō-ˈī-sə-ˌtōp 

: a radioactive isotope

Medical Definition

radioisotope

noun

ra·​dio·​iso·​tope ˌrād-ē-ō-ˈī-sə-ˌtōp 

: a radioactive isotope compare radioelement

radioisotopic

-ˌī-sə-ˈtäp-ik, -ˈtōp-ik 

adjective

radioisotopically

-i-k(ə-)lē 

adverb