Working out a cryptogram is the process of decoding a message that has been encrypted using a cipher. A cipher is a type of code that replaces letters, symbols, or words with other letters, symbols, or words. The goal of working out a cryptogram is to decipher the original message by substituting the correct letters for the encrypted ones. The term 'work out a cryptogram' can also refer to the process of creating a cryptogram, which involves encrypting a message using a cipher.