
0, zero, cipher, cypher, nought  a mathematical element that when added to another number yields the same number  

nothing, zero, naught, zip, cipher, cypher, nil, nix, nada, null, aught, goose egg, zilch, zippo  a quantity of no importance  
V2 
cipher, encipher, cypher, inscribe, code, encrypt, write in code  convert ordinary language into code  

cryptograph, cipher, cypher, secret code  a secret method of writing  

nobody, cipher, cypher, nonentity  a person of no influence  

cipher, cypher  a message written in a secret code  
V2 
compute, calculate, figure, reckon, work out, cipher, cypher  [in mathematics] make a mathematical calculation or computation 