background radiation

noun

: the microwave radiation pervading the universe that exhibits a corresponding blackbody temperature of 2.7 K and that is the principal evidence supporting the big bang theory

called also cosmic background radiation

Examples of background radiation in a Sentence

Recent Examples on the Web

Last year, for example, NASA’s Curiosity rover recorded a solar storm that generated 100 days’ worth of the Milky Way’s normal background radiation over the span of a single day. —Andrew Paul, Popular Science, 6 Nov. 2025

Natural background radiation varies globally between 1 to 10 mGy per year depending on altitude, soil composition, and building materials. —Anna Broughel, Forbes.com, 7 Sep. 2025

All of the nests discovered at the site emitted less than 1% of the natural background radiation that all humans experience daily, according to the SRS. —Julia Jacobo, ABC News, 7 Aug. 2025

As atmospheric nuclear testing ended and background radiation returned to natural levels, low-background steel eventually became unnecessary for most uses. —ArsTechnica, 18 June 2025

Word History

First Known Use

1968, in the meaning defined above

Rhymes for background radiation

• abbreviation
• abomination
• acceleration
• accentuation
• accommodation
• accreditation
• acculturation
• accumulation
• acetylation
• adjudication
• administration
• adulteration