code word
US /ˈkoʊd wɜːrd/
UK /ˈkoʊd wɜːrd/

1.
palabra clave, contraseña
a word or phrase that has a secret meaning and is used to give a message or signal
:
•
The spies used a specific code word to identify each other.
Los espías usaban una palabra clave específica para identificarse entre sí.
•
Only those who knew the code word were allowed to enter.
Solo aquellos que conocían la palabra clave tenían permitido entrar.