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

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

The photos show light, dark and the polarization of light—background radiation known as the cosmic microwave background, and details the movement of hydrogen and helium gas at the beginning of the universe. —Dan Perry, Newsweek, 18 Mar. 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