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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Israel's military said its fighter jets targeted the Arak heavy water reactor, some 155 miles southwest of Tehran, to prevent it from being used to produce plutonium. Arkansas Online, 20 June 2025 Iran agreed to redesign Arak to address nuclear concerns Israel’s military said Thursday its fighter jets targeted the Arak heavy water reactor, some 155 miles southwest of Tehran, in order to prevent it from being used to produce plutonium. Sam Mednick, Los Angeles Times, 19 June 2025 The Israeli military, meanwhile, struck a heavy water reactor part of Iran’s nuclear program. Sarah Fortinsky, The Hill, 19 June 2025 The Arak heavy water reactor 155 miles southwest of Tehran on Saturday. Sara Monetta, NBC news, 19 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 1 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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