An Etymological Dictionary of Astronomy and Astrophysics

1. A system used for brevity or secrecy of communication, in which arbitrarily chosen words, letters, or symbols are assigned definite meanings.
   

2. Computers: The symbolic arrangement of statements or instructions in a computer program in which letters, digits, etc. are represented as binary numbers; the set of instructions in such a program (Dictionary.com).

Etymology (EN): M.E., from O.Fr. code, from L. codex “book, book of laws,” later form of caudex
“tree trunk,” hence “document made up of wooden tablets.”

Etymology (PE): Ramz “secret writing, enigma,” loan from Ar.