Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “cipher”

cipher

noun [C] (SECRET WRITING)   /ˈsɑɪ·fər/
a system of writing that most people cannot understand, so that the message is secret; a code: We spent a lot of time figuring out the enemy’s cipher.
(Definition of cipher noun (SECRET WRITING) from the Cambridge Academic Content Dictionary © Cambridge University Press)
Focus on the pronunciation of cipher

More American English definitions for “cipher”

Definitions of “cipher” in other dictionaries

Word of the Day

closeness

the quality of knowing someone very well, liking them a lot, and wanting to spend a lot of time together

Word of the Day

Blog

Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More