code

Etymology 1

From Middle English code (“system of law”), from Old French code (“system of law”), from Latin cōdex, later form of caudex (“the stock or stem of a tree, a board or tablet of wood smeared over with wax, on which the ancients originally wrote; hence, a book, a writing.”). Doublet of codex.

noun

1. A short symbol, often with little relation to the item it represents.
   This flavour of soup has been assigned the code WRT-9.
2. A body of law, sanctioned by legislation, in which the rules of law to be specifically applied by the courts are set forth in systematic form; a compilation of laws by public authority; a digest.
   the mild and impartial spirit which pervades the Code compiled under Canute 1872, Francis Wharton, A Treatise on the Conflict of Laws
3. Any system of principles, rules or regulations relating to one subject.
   The medical code is a system of rules for the regulation of the professional conduct of physicians.
   The naval code is a system of rules for making communications at sea by means of signals.
4. A set of rules for converting information into another form or representation.
   1. By synecdoche: a codeword, code point, an encoded representation of a character, symbol, or other entity.
      The ASCII code of "A" is 65.
5. A message represented by rules intended to conceal its meaning.
   [Isaac Newton] was obsessed with alchemy. He spent hours copying alchemical recipes and trying to replicate them in his laboratory. He believed that the Bible contained numerological codes. 2014-06-21, “Magician’s brain”, in The Economist, volume 411, number 8892
6. (cryptography) A cryptographic system using a codebook that converts words or phrases into codewords.
7. (programming, uncountable) Instructions for a computer, written in a programming language; the input of a translator, an interpreter or a browser, namely: source code, machine code, bytecode.
   Object-oriented C++ code is easier to understand for a human than C code.
   I wrote some code to reformat text documents.
   This HTML code may be placed on your web page.
8. (scientific programming) A program.
9. (linguistics) A particular lect or language variety.
10. (medicine) An emergency requiring situation-trained members of the staff.
11. (informal) A set of unwritten rules that bind a social group.
    girl code

verb

1. (computing) To write software programs.
   I learned to code on an early home computer in the 1980s.
2. (transitive) To add codes to (a data set).
   The resulting citation collection was databased and coded for meaning, etymon, and date range (earliest and latest occurrence found). 2018, James Lambert, “A multitude of ‘lishes’: The nomenclature of hybridity”, in English World-Wide, page 5
3. To categorise by assigning identifiers from a schedule, for example CPT coding for medical insurance purposes.
4. (cryptography) To encode.
   We should code the messages we send out on Usenet.
5. (genetics, intransitive) To encode a protein.
6. (medicine) To call a hospital emergency code.
   coding in the CT scanner
7. (intransitive, medicine) To go into a state where a hospital emergency code is required to save one's life.
   He coded out of nowhere

Etymology 2

From code blue, a medical emergency.

verb

1. (medicine) Of a patient, to suffer a sudden medical emergency (a code blue) such as cardiac arrest.