AGN

American

abbreviation

Astronomy. active galactic nucleus.

AGN British

abbreviation

active galactic nucleus See active galaxy

"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.

"This dramatic layering of young jets inside older, exhausted lobes is the signature of an episodic AGN -- a galaxy whose central engine keeps turning on and off over cosmic timescales."

From Science Daily • Apr. 13, 2026

Dutch insurer and asset manager Aegon AGN -7.64%decrease; red down pointing triangle plans to relocate its business to the U.S. and rebrand as Transamerica Inc., a move aimed at accelerating growth in the region.

From The Wall Street Journal • Dec. 10, 2025

"The AGN has endorsed Ethiopia," Richard Muyungi, the group's chair told AFP.

From Barron's • Nov. 11, 2025

They came up with one, known as ZTF20aaglfpy, that showed the most change between its Sloan sighting in 2003 and their new observations in 2022, which showed signs of a rapidly growing AGN.

From Science Magazine • Jun. 17, 2024

But quasars are an AGN that are even more intense.

From Salon • Apr. 30, 2023

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