su·​per·​heavy ˌsü-pər-ˈhe-vē How to pronounce superheavy (audio)
: extremely heavy
superheavy furniture
superheavy traffic
a superheavy discussion with his mother
especially, chemistry : relating to or being a chemical element with a greater atomic mass than that of uranium
The existence of superheavy elements, those with many more protons than uranium (proton number 92), was predicted more than 40 years ago. Georg Bollen
superheavy noun
plural superheavies
In February the world was treated to a transcontinental eureka moment: Scientists … announced they had discovered two new chemical elements. Called superheavies because of their large atomic mass, elements 113 and 115 lasted little more than a second. Elizabeth Svoboda

Word History

First Known Use

1822, in the meaning defined above

Time Traveler
The first known use of superheavy was in 1822

Dictionary Entries Near superheavy

Cite this Entry

“Superheavy.” Dictionary, Merriam-Webster, Accessed 3 Dec. 2022.

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