✨📕 The NEWThe NEW Collegiate Dictionary, 12th Edition Over 5,000 words added — Buy Now! Collegiate DictionaryBuy Now!

rem

1 of 2

noun (1)

: the dosage of an ionizing radiation that will cause the same biological effect as one roentgen of X-ray or gamma-ray exposure

Examples of rem in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Noun
In April, more than 200 musicians, including Billie Eilish, REM, Stevie Wonder, signed an open letter organized by the Artists’ Rights Alliance to ask tech companies to stop devaluing music. Jennifer Kite-Powell, Forbes.com, 28 Aug. 2025
Noun
When cells exceed 50°C, the charging power must be reduced to prevent lithium plating and long-term damage, which can cause fast charging to taper off earlier than advertised and significantly extend overall charge times, according to Renewable Energy Magazine (REM). Jijo Malayil, Interesting Engineering, 16 Nov. 2025 In April, more than 200 musicians, including Billie Eilish, REM, Stevie Wonder, signed an open letter organized by the Artists’ Rights Alliance to ask tech companies to stop devaluing music. Jennifer Kite-Powell, Forbes.com, 28 Aug. 2025

Word History

Etymology

Noun (1)

roentgen equivalent man

First Known Use

Noun (1)

1947, in the meaning defined above

Noun (2)

1957, in the meaning defined above

Time Traveler
The first known use of rem was in 1947

Browse Nearby Words

Cite this Entry

“Rem.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/rem. Accessed 29 Nov. 2025.

Kids Definition

Medical Definition

rem

1 of 2 noun
: the dosage of an ionizing radiation that will cause the same biological effect as one roentgen of X-ray or gamma-ray dosage compare rep

REM

2 of 2 noun

More from Merriam-Webster on rem

Last Updated: - Definition revised
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!