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

According to the Department of Energy, its Nuclear Emergency Support Team will be conducting routine background radiation surveys in the days leading up to the game, a standard security measure for major events. —Steve Large, CBS News, 4 Feb. 2026

Some fallout particles remain aloft at high altitudes for a very long period, raising the overall global background radiation by a small but detectable amount. —Davis Winkie, USA Today, 6 Jan. 2026

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

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