Oort

British

/ ɔːt /

noun

Jan Hendrick. 1900–92, Dutch astronomer, who confirmed (1927) and developed the theory of galactic rotation. He was the first to propose (1950) the existence of a mass of comets orbiting the sun far beyond the orbit of Pluto (the Oort cloud )

"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

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.

In 1998, he told me that we would someday live in the Oort Cloud.

From Slate • Dec. 9, 2025

And what, you ask, is the Oort Cloud?

From Los Angeles Times • Oct. 11, 2024

The Oort Cloud, a hypothesized shell of icy worlds at an unfathomable distance from the sun, has never been directly seen—and VRO won’t change that.

From National Geographic • Jan. 9, 2024

Given the size and distance of the Oort cloud, though, we may never know for sure what's lurking out there.

From Scientific American • Jun. 28, 2023

Pluto is about forty AUs from us, the heart of the Oort cloud about fifty thousand.

From "A Short History of Nearly Everything" by Bill Bryson

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023