Collins COBUILD Advanced Learner's English Dictionary - code name

also codename, code-name (code names, code naming, code named) 1. A code name is a name used for someone or something in order to keep their identity secret. One of their informers was working under the code name Czerny... N-COUNT: usu N n 2. If a military or police operation is code-named something, it is given a name which only the people involved in it know. The operation was code-named Moonlight Sonata. ...a military contingent, code-named Sparrowhawk. VERB: usu passive, be V-ed n, V-ed