From Longman Dictionary of Contemporary Englishcode nameˈcode name noun [countable]SECRETa name that is used to keep someone’s or something’s real name a secret —code-name verb [transitive]
a crime busting operation code-named JeevesExamples from the Corpuscode name• The new system was as deep and mysterious as its chromaticcode nameimplied.• He decided to give the various systems code namesbased on the colors of the spectrum.• Medusa was the code name of a back-up disksuiteproduct brought to market a year ago.• It was preceded by a scrupulousrecce weeks before in a restaurantnear his house with the code name Pomme d'Amour.• The Triumphcode name, by the way, has been changed.• Fascination with code names went well beyondoperations, reaching even the contra supporters and fund-raisers.
