code word
word or phrase designed to convey a predetermined meaning to an audience who know the phrase, while remaining inconspicuous to the uninitiated
en-GB/ˈkəʊd ˈwɜːd/
en-US/ˈkoʊd ˈwɝd/
word or phrase designed to convey a predetermined meaning to an audience who know the phrase, while remaining inconspicuous to the uninitiated