a name assigned to conceal the real identity of a person, as a spy, or to conceal the existence or purpose of a plan, military operation, etc.
Also called code phrase. a word or phrase assigned a meaning understood only by those who are secretly informed of it.
First recorded in 1915–20
First recorded in 1955–60
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
They referred to the possibility of their characters getting a call from Sweden by a code name: ABBA.
From The Wall Street Journal • Jan. 17, 2026
The latter is salient because the name Oracle comes from the code name of a CIA-funded project that Ellison worked on.
From Barron's • Oct. 10, 2025
He said company lawyers had come up with a code name for the deal — Project USA — to help maintain a level of secrecy.
From New York Times • May 1, 2024
Operation Interflex is the code name given to the UK Armed Forces' training programme, which has been created to develop and prepare Ukrainian recruits to fight their country's Russian invaders.
From BBC • Feb. 24, 2024
Our scholar-diplomat, Magister Brangwain Spurge, code name: “The Weed,” has at this point been in the goblin capital of Tenebrion for eighteen hours.
From "The Assassination of Brangwain Spurge" by M.T. Anderson and Eugene Yelchin
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
