code

American  

[kohd] / koʊd /

noun

1. a system for communication by telegraph, heliograph, etc., in which long and short sounds, light flashes, etc., are used to symbolize the content of a message.

   Morse code.

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

3. indirect wording that is euphemistic, deceptive, or opaque.

   The firm says its testing methodology is “proprietary”—which some believe is code for “hidden from scrutiny.”

4. any set of standards set forth and enforced by a local government agency for the protection of public safety, health, etc., as in the structural safety of buildings building code, health requirements for plumbing, ventilation, etc. sanitary code or health code, and the specifications for fire escapes or exits fire code.

5. a systematically arranged collection or compendium of laws, rules, or regulations.

6. any authoritative, general, systematic, and written statement of the legal rules and principles applicable in a given legal order to one or more broad areas of life.

7. a word, letter, number, or other symbol used in a code system to mark, represent, or identify something.

   The code on the label shows the date of manufacture.

8. Computers.

   1. a set of symbols that can be interpreted by a computer or piece of software: Java code;

      binary code;

      Java code;

      ASCII code.

   2. the symbolic arrangement of statements or instructions in a computer program, or the set of instructions in such a program.

      That program took 3000 lines of code.

9. any system or collection of rules and regulations.

   a gentleman's code of behavior.

10. Medicine/Medical. a directive or alert to a hospital team assigned to emergency resuscitation of patients.

11. Genetics. genetic code.

12. Linguistics.

    1. the system of rules shared by the participants in an act of communication, making possible the transmission and interpretation of messages.

    2. (in sociolinguistic theory) one of two distinct styles of language use that differ in degree of explicitness and are sometimes thought to be correlated with differences in social class.

---

verb (used with object)

coded, coding

1. to translate (a message) into a code; encode.

2. to categorize or identify by assigning a code to.

   All specimens were coded prior to the test.

3. to arrange or enter (laws or statutes) in a code.

4. Computers. to write code for (a computer program or application) (often followed byup ).

   Hire a programmer to code up a website for you.

verb (used without object)

coded, coding

1. Genetics. to specify the amino acid sequence of a protein by the sequence of nucleotides comprising the gene for that protein.

   a gene that codes for the production of insulin.

2. Computers. to write computer code.

code British  

/ kəʊd /

noun

1. a system of letters or symbols, and rules for their association by means of which information can be represented or communicated for reasons of secrecy, brevity, etc See also genetic code

   binary code

   Morse code

2. a message in code

3. a symbol used in a code

4. a conventionalized set of principles, rules, or expectations

   a code of behaviour

5. a system of letters or digits used for identification or selection purposes

---

verb

1. to translate, transmit, or arrange into a code

code Scientific  

/ kōd /

1. A system of signals used to represent letters or numbers in transmitting messages.

2. The instructions in a computer program. Instructions written by a programmer in a programming language are often called source code. Instructions that have been converted into machine language that the computer understands are called machine code or executable code.

3. See also programming language

---

code Cultural  

1. A series of instructions designed to be fed into a computer.

---

Other Word Forms

• codeless adjective
• coder noun
• precode verb (used with object)
• recode verb (used with object)
• subcode noun

Etymology

Origin of code

First recorded in 1275–1325; Middle English, from Anglo-French, Old French, from Latin cōdex “book”; codex

Explanation

A code can be a set of principles. Our laws make up our legal code, and many people govern themselves through a personal "code of honor." Code can also mean a system for sending secret messages, or programming language for computers. In 1303, you could only use code to mean a set of laws, such as a code of conduct. It wasn’t until 1808 that you could use code to describe a system for sending secret messages. The verb form appeared in 1815, meaning to create laws or send secret messages, and gave birth to encode. In the computer programming context, encode was shortened back again to code, meaning to write instructions for a computer program. Soon the lines of text themselves began to be referred to as simply code.

Example Sentences

Masters organisers are known for their strict rules and code of conduct for players and fans - known as patrons - attending the tournament.

From BBC • Apr. 10, 2026

According to Anthropic and partners, Mythos can autonomously scan vast amounts of code to find and chain together previously unknown security vulnerabilities in all kinds of software, from operating systems to web browsers.

From Barron's • Apr. 10, 2026

AI-powered tools can generate text, images, code and help with other tasks such as planning and research.

From Los Angeles Times • Apr. 8, 2026

Open-sourcing a model gives the public access to some parts of the code and other architecture behind it.

From The Wall Street Journal • Apr. 8, 2026

The leading Polish code breakers—mathematicians called Jerzy Rózycki, Henryk Zygalski, and Marian Rejewski—had been working on Enigma for nearly ten years.

From "The Bletchley Riddle" by Ruta Sepetys and Steve Sheinkin

Related Words

• constitution
• convention
• custom
• discipline
• laws
• regulation
• rules
• system