code name 
noun
A word used for secrecy or convenience instead of the usual name: using the code name ‘Charlie’, Dick was on the phone with the President more and more...
- I don't known why the Secret Service gives out the code name, but his code name is Tumbler.
- We don't know if that's his real name or a code name.
- Ah, he does not want me to say his name but he has given me a code name.
- sanitation
- sanitise
- sanitization
- sanitize
- sanitizer
- sanity
- San Jacinto River
- sanjak
- San Joaquin River
- San Joaquin Valley fever
- San Jose
- San José
- San Juan
- San Juan Capistrano
- San Juan Hill
- San Juan Islands
- San Juan Mountains
- sank
- San Leandro
- San Luis Obispo
- San Luis Potosí
- San Marcos
- San Marino
- San Martín, José de
- San Mateo