code

SayKOHDUS/koʊd/UK/kəʊd/

Pluralcodes

Verbcodes, coding, coded

14 meanings of code

Practice

1
nouncountable or uncountable
A letter, number, symbol, or combination of these that is assigned to identify or represent something, such as a product, place, or character.
Every shipment is tagged with a code that the system tracks automatically.
The airline assigns a three-letter code to each destination.
UsageCommon: a code for something, enter the code, zip code, postal code.
Similaridentifier, symbol, label
2
computer instructionsnoununcountable
Instructions for a computer written in a programming language, such as source code, machine code, or bytecode.
Engineers reviewed the code before pushing it to the live server.
Most of the code in this app handles user authentication.
UsageWrite code, lines of code (not ~~incorrect: write a code~~). The language often comes first: Python code.
Similarsoftware
3
nouncountable or uncountable
A set of rules, principles, or standards that govern behavior or activity within a particular group, profession, or field, whether written down or not.
Doctors are bound by a professional code that puts patients first.
The newsroom adopted a code governing how reporters handle sources.
UsageCommon: dress code, code of conduct, code of ethics. People follow or break a code.
Similarethic, policy
4
collected lawsnouncountable or uncountable
A body of law established by legislation, in which the rules courts apply are set out in systematic form.
The civil code governs contracts and property throughout the region.
The judge read the relevant section of the penal code aloud to the jury.
UsageOften the penal code, the tax code, the civil code.
Similarlaw, regulations, legislation, statute
Note
The sense the word arrived in English with: Middle English and Old French code meant a system of law. A named compilation takes a capital, as when Francis Wharton in 1872 praises the spirit of the Code compiled under Canute.
Checked 2 Nov 2026 · 1 fact
English code originated in the legal sense, through Middle English and Old French words meaning a system of law. en.wiktionary.org
5
write programsverbtransitive or intransitive
To write software programs.
He likes to code late at night when the office is quiet.
They code in several different languages at the firm.
UsageMostly without an object: learn to code, code in Python.
Similarprogram, develop
6
symbol systemnouncountable or uncountable
A system of fixed rules by which information is turned into some other form or representation.
The telegraph relied on a code that turned letters into dots and dashes.
Designers chose a code that packs each color into three numbers.
Similarencoding, scheme
7
verbtransitive
To convert a message or information into a coded form.
Operators had to code every message before transmitting it.
They code sensitive files so outsiders cannot read them.
UsageCode a message or a file. Encode means the same.
Similarencode, encrypt, encipher
Oppositedecode, decrypt, decipher
Note
Strictly it belongs with the codebook system, which replaces whole words and phrases. In looser use it covers any scheme for hiding meaning, including letter-by-letter ciphers.
Checked 2 Nov 2026 · 1 fact
A cryptographic codebook supplies replacements for whole words and phrases. en.wikipedia.org
8
make proteinverbintransitive
To carry the genetic information that specifies a particular protein.
Many genes code for proteins that regulate metabolism.
This stretch of DNA codes for hemoglobin.
UsageTakes for: a gene codes for a protein. With a direct object, use encode.
Similarencode
Note
The sequence specifies the protein's amino acids through triplet codons read during translation.
Checked 2 Nov 2026 · 1 fact
The nucleotide sequence specifies a protein's amino acids through three-nucleotide codons read during translation. medlineplus.gov
9
verbtransitive
To mark items in data, records, or diagnoses with codes from a set system so they can be grouped, analyzed, or billed.
Researchers code the transcripts line by line.
The team coded every survey answer for sentiment.
UsageOften code data for a feature or by a category: answers coded for sentiment.
Similartag, label, categorize, classify
10
nouncountable or uncountable
A system of words, letters, or symbols used in place of others to keep a message secret, or a message written in such a system, as in 'sent in code'.
The agents' code replaced each place name with an ordinary-sounding word drawn from a shared codebook.
Breaking the enemy's code meant first capturing the codebook itself.
UsageOften in code: a message written in code. People break or crack a code.
Note
Cryptographers draw a line that everyday speech blurs. A code works on whole words or phrases looked up in a codebook. A cipher transforms individual letters or symbols by a rule, so a "secret code" is often really a cipher. The distinction matters in practice: breaking a code usually means recovering or reconstructing the book rather than working out a rule, and that is what turns a coded message back into readable text.
Checked 31 Oct 2026 · 4 facts
Cryptography distinguishes codes from ciphers, although everyday language treats them interchangeably. en.wikipedia.org
Codes represent meaningful units such as words and phrases through codebook equivalents. nsa.gov
Ciphers transform characters rather than substituting for meaningful words or phrases. archives.fbi.gov
Breaking a code involves recovering the correspondences between codegroups and plaintext, enabling the message to be read. en.wikipedia.org

Less common meanings

11
suffer emergencyverbintransitive
Of a patient, to undergo a sudden life-threatening emergency such as cardiac arrest.
Patients can code suddenly, even after hours of stable readings.
The man in bed four coded at three in the morning.
UsageHospital jargon. In everyday English, name the emergency: went into cardiac arrest, stopped breathing.
Similarcrash, arrest
Note
A shortening of code blue, the hospital alert for a medical emergency: the name of the call became a verb for what happens to the patient.
Checked 2 Nov 2026 · 2 facts
The medical verb derives from a shortening of code blue, transferring the alert's name to the patient's emergency. en.wiktionary.org
Code blue is a hospital alert for a medical emergency. my.clevelandclinic.org
12
nouncountable or uncountable
A hospital emergency that requires specially trained staff to respond immediately.
The charge nurse called a code the instant the patient stopped breathing.
A code sent half the floor sprinting toward the same room.
UsageUsually call a code; the best-known alert is code blue.
Note
Each kind of crisis summons staff trained for it, and the best-known alert is code blue. That alert's name later became a verb for a patient in sudden crisis.
Checked 2 Nov 2026 · 2 facts
Emergency codes activate the personnel needed for the particular emergency. archive.hasc.org
The medical verb code derives from code blue. en.wiktionary.org
13
call emergencyverbtransitive or intransitive
To call a hospital emergency code, summoning a response team to a patient in crisis.
Within seconds of the monitor alarm, the night nurse coded the patient in bed six and the team came running.
New residents learn exactly when to code a patient and when to call the rapid response team instead.
Note
Here the subject is the staff, not the patient. A team coding in the CT scanner is running an emergency response there. Keep the verb apart from the patient's own crisis, where the person who codes is the one in danger.
14
language varietynouncountable or uncountable
A particular language or language variety used by a speaker or community.
Bilingual speakers often switch from one code to another in the middle of a sentence.
In formal settings she adopted a more prestigious code.
UsageCommon in code-switching; speakers switch codes or choose a code.
Similarlanguage, variety, dialect, register
Note
Linguistics borrows the word as a neutral cover term for any language, dialect or style of speech. It spares the analyst from deciding whether a variety counts as a "language" or a "dialect." The use is most familiar from code-switching, the practice of moving between two varieties within one conversation or even one sentence.
Checked 2 Nov 2026 · 1 fact
Linguistics adopted “code” as a technical term borrowed from another field. journals.colorado.edu

Practice

Can you tell the meanings of code apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origins

Meanings 1–10, 12–14

From Middle English "code" (system of law), from Old French "code," from Latin "cōdex," a later form of "caudex" (the stock or stem of a tree, and also a wax-covered wooden tablet the ancients wrote on, hence a book or writing). It is a doublet of "codex."

Checked 31 Oct 2026 · 5 facts

English code comes through Middle English code, meaning a system of law, and Old French code from Latin cōdex. en.wiktionary.org
Latin cōdex is a later form of caudex. alatius.com
Caudex meant the stock or stem of a tree. alatius.com
Caudex also referred to wooden writing tablets, which were wax-covered in antiquity, and hence to a book or writing. alatius.com
Code and codex are etymological doublets. en.wiktionary.org

Meaning 11

From "code blue," a term for a medical emergency.

Checked 31 Oct 2026 · 2 facts

The medical sense of code comes from code blue. en.wiktionary.org
Code blue denotes a medical emergency. en.wiktionary.org