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

Late last week saw attacks on the nuclear power facility in Bushehr, a yellowcake production site in Yazd province, and a heavy water facility in Khondab, according to statements from the International Atomic Energy Agency. —Micah McCartney, MSNBC Newsweek, 31 Mar. 2026

Why the Khondab site matters The Khondab plant produces heavy water, a material used to cool certain types of nuclear reactors. —Sujita Sinha, Interesting Engineering, 30 Mar. 2026

Over the weekend, the IDF struck two steel plants in Iran, including one that uses radioactive material, the UN’s nuclear watchdog said, as well as a heavy water plant in Arak, which includes key production sites for plutonium. —Sophie Tanno, CNN Money, 29 Mar. 2026

The International Atomic Energy Agency concluded Sunday that Iran’s Khondab heavy water production plant had sustained severe damage from a strike. —Patrick Sykes, Fortune, 29 Mar. 2026

Word History

First Known Use

1933, in the meaning defined at sense 1

Rhymes for heavy water

• annunciator
• imprimatur
• underwater
• backwater
• bathwater
• blackwater
• breakwater
• deepwater
• edgewater
• feedwater
• floodwater
• freshwater

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