English Reference
verb · noun

decipher

v. · n.
US /dɪˈsaɪfɝ/ UK /dɪsˈaɪfɐ/ de·ci·pher UK spelling deciphered, deciphers

  1. 01 B2 Upper Intermediate Technical Computing

    v.to change a secret message or code into plain language so you can understand it.

    v.to convert a text written in code or cipher into plain language.

    Simple

    The experts worked for weeks to decipher the enemy's secret radio signals.

    In context

    During the war, mathematicians at Bletchley Park worked tirelessly to decipher messages encrypted by the Enigma machine.

    Usage

    Transitive; always requires a direct object representing the code or message.

    decodedecrypt
  2. 02 B2 Upper Intermediate

    v.to succeed in reading something that is very messy or hard to see.

    v.to interpret or read text that is nearly illegible, obscure, or poorly written.

    Simple

    I spent ten minutes trying to decipher my doctor's messy handwriting on the note.

    In context

    The historian spent years in the archives attempting to decipher the faded ink on the medieval parchment.

    readmake outinterpret
  3. 03 C1 Advanced Academic

    v.to figure out the meaning of something complicated or confusing.

    v.to discern the meaning of a complex, ambiguous, or confusing situation or set of data.

    Simple

    It was hard to decipher his true feelings because he rarely showed any emotion.

    In context

    Economists are still struggling to decipher the long-term implications of the sudden market shift.

    Teacher's tip

    This sense is often used metaphorically for human behavior or abstract data.

  4. 04 C2 Proficiency FormalTechnical

    n.the act of solving a code or understanding a difficult text.

    n.the process or result of decoding or interpreting obscure information.

    Simple

    The decipher of the ancient tablet changed how we view that civilization.

    In context

    The successful decipher of the manuscript provided unprecedented insights into the linguistic evolution of the region.

    deciphermentdecoding

And navigating a website might involve deciphering images or knowing what links to click.

The Conversation· 25 Aug 2026

It is difficult to decipher if Cruzeiro’s Jonathan Jesus would sign for Strasbourg or Chelsea, but the talk in Brazil is that ownership group BlueCo want the 22-year-old centre-back.

The Guardian· 24 Aug 2026

As decypher, but not retaining the y from the Old French etyma of cipher (cyfre, cyffre); the i spelling tends to be preferred etymologically, being consistent with its cognates, the French déchiffrer and the Italian decifrare, and with their common ancestor, the Medieval Latin cifra, cifera, ciphra. By surface analysis, de- + cipher.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level C1 · Advanced
Frequency Occasional
Updated