heavy water

noun

1
: the compound D2O composed of deuterium and oxygen

called also deuterium oxide

2
: water enriched in deuterium

Examples of heavy water in a Sentence

Recent Examples on the Web
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Most of Iran's nuclear program centered around uranium, but the nation had also built but never started a heavy water reactor that could potentially produce plutonium, another important material for nuclear weapons. Geoff Brumfiel, NPR, 26 June 2025 Israel, meanwhile, carried out strikes on Iran’s Arak heavy water reactor. Kristina Karisch, The Hill, 19 June 2025 But its cover was blown in December 2002, when satellite photos emerged showing an enrichment site in the city of Natanz and a heavy water plant about 200 miles away in Arak. Dan De Luce, NBC news, 28 June 2025 Israel took out top generals and nuclear scientists and destroyed nuclear facilities in Natanz, Isfahan and the Arak heavy water reactor, Netanyahu said. Melanie Lidman, Chicago Tribune, 24 June 2025 See All Example Sentences for heavy water

Word History

First Known Use

1933, in the meaning defined at sense 1

Time Traveler
The first known use of heavy water was in 1933

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Cite this Entry

“Heavy water.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/heavy%20water. Accessed 21 Jul. 2025.

Kids Definition

heavy water

noun
: water enriched in deuterium

Medical Definition

heavy water

noun
1
: the compound D2O composed of deuterium and oxygen

called also deuterium oxide

2
: water having a higher-than-usual proportion of deuterium among its hydrogen atoms

More from Merriam-Webster on heavy water

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