also codename, code-name
(~s, code naming, ~d)
1.
A ~ is a name used for someone or something in order to keep their identity secret.
One of their informers was working under the ~ 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