cipher
ci•pher (also cy•pher)BrE /ˈsaɪfə(r)/
NAmE /ˈsaɪfər/
noun1 [uncountable, countable] a secret way of writing, especially one in which a set of letters or symbols is used to represent others 
word origin
code
a message in cipher 
see also decipher 2 [countable] (formal, disapproving) a person or thing of no importanceTo her employers she was a mere cipher, with no human feelings at all. 3 (BrE) the first letters of sb's name combined in a design and used to mark thingsThe glasses were engraved with the Queen's cipher.
