su·​per·​moon ˈsü-pər-ˌmün How to pronounce supermoon (audio)
plural supermoons
: a full moon occurring when the moon is at or near the closest point in its orbit
A supermoon … occurs when the moon is full within 24 hours of being at its closest point to the Earth in its orbit. Kaleigh Rogers
Visible supermoons appear 14% bigger and 30% brighter than full moons that occur at the farthest point in the moon's orbit. Karen Hao
As the first and only supermoon of 2017 rose high into the sky this Sunday (Dec. 3), astrophotographers seized the opportunity to shoot the moon in all its bigger-than-usual glory. Hanneke Weitering

Word History

First Known Use

1979, in the meaning defined above

Time Traveler
The first known use of supermoon was in 1979

Dictionary Entries Near supermoon

Cite this Entry

“Supermoon.” Dictionary, Merriam-Webster, Accessed 8 Dec. 2022.

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