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Iapetus

American  
[ahy-ap-i-tuhs, ee-ap-] / aɪˈæp ɪ təs, iˈæp- /

noun

  1. Classical Mythology. a Titan, son of Uranus and Gaia.

  2. Astronomy. a natural satellite of the planet Saturn.


Iapetus British  
/ aɪˈæpɪtəs /

noun

  1. a large outer satellite of the planet Saturn

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of Iapetus

First recorded in 1600–20; Latin Īapetus, from Greek Īapetós; further origin uncertain; probably from the same source as Hebrew Yepheth; Japheth ( def. )

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The team also found that before it disappeared, Proto-Hyperion could have tilted the orbit of Saturn's distant moon Iapetus, potentially solving another longstanding mystery about the Saturn system.

From Science Daily • Feb. 27, 2026

In the book you mention that you like Saturn’s moon Iapetus because of its different hemispheres and describe how that idea of polarity is compelling to you.

From Scientific American • Jul. 24, 2023

In some, the lost moon collided with Titan or Iapetus; in others it was ejected from the Saturn system altogether.

From Science Magazine • Sep. 14, 2022

Our favorites include Uranus’ Miranda, with its jigsaw puzzle surface; Saturn’s Mimas, with a “knockout” crater called Herschel; and Saturn’s Iapetus, whose two hemispheres differ significantly.

From Textbooks • Oct. 13, 2016

He wondered what had happened to Iapetus after they’d left him in Hades’s palace...if he was still content being Bob, friendly, happy, and clueless.

From "The House of Hades" by Rick Riordan