Meaning of CODE in English

(LANGUAGE) [noun] [C] - a system of words, letters or signs which is used to represent a message in secret form, or a system of numbers, letters or signals which is used to represent something in a shorter or more convenient formThe message was written in code. [U]She managed to decipher/break/crack (= succeed in understanding) the code. [C]A person's postal address is identified by their (UK and ANZ) post/(US) zip code. [C]Each entry in this dictionary has a grammar code. [C]What is the (UK)dialling/(US and ANZ) area code for Birmingham?A code name is a special word or sign which is used instead of the real name of someone or something to keep the real name secret.Her code name is 'Running bear'.This mission is code-named 'Ice-breaker'.

Cambridge English vocab.      Кембриджский английский словарь.