codeyoudaoicibaDictYouDict[code 词源字典]
code: [14] ‘System of secret communication signs’ is a relatively recent semantic development of the word code, which emerged in the early 19th century. It derived from an earlier sense ‘system of laws’, which was based on a specific application to various sets of statutes introduced by the Roman emperors. The word itself came from Old French code, a descendant of Latin cōdex, whose meaning ‘set of statutes, book of laws’ derived from a broader sense ‘book’.

This in turn came from an earlier ‘piece of wood coated with wax for writing on’, which was based ultimately on ‘tree trunk’, the word’s original meaning. Codex itself was borrowed into English in the 16th century. Its Latin diminutive form, cōdicillus, produced English codicil [15].

=> codex, codicil[code etymology, code origin, 英语词源]
code (n.)youdaoicibaDictYouDict
c. 1300, "systematic compilation of laws," from Old French code "system of laws, law-book" (13c.), from Latin codex, earlier caudex "book, book of laws," literally "tree trunk," hence, book made up of wooden tablets covered with wax for writing. Meaning "cipher" (the sense in secret code) is from 1808.
code (v.)youdaoicibaDictYouDict
1815, from code (n.). Specifically in the computer sense from 1947. Related: Coded; coding.