cipher

Pluralciphers

Formsciphers, ciphering, ciphered

1. 1
   nouncountable

   A method or system for disguising a message by replacing or rearranging its letters or bits according to a set rule, so that only someone with the key can read it.

   Email encryption tools often rely on a public-key cipher, so anyone can lock a message but only the recipient can open it.

   Researchers found a flaw in the cipher that let them recover the key in a few hours.

   UsageOften confused with code: a cipher changes letters or bits by a rule, while a code swaps whole words. You break or crack a cipher.

   Note

   In computing the cipher is the algorithm itself, what it produces is ciphertext, and a public-key cipher locks a message with one key and opens it with a different one. Source

   Checked 2 Nov 2026 · 3 facts

   • A cipher is the encryption and decryption algorithm. rfc-editor.org
   • Encrypted output is called ciphertext. csrc.nist.gov
   • Public-key encryption uses different keys for encryption and decryption. csrc.nist.gov
2. 2
   coded textnouncountable

   A message whose meaning has been concealed by a cipher; ciphertext.

   The note on the back of the photograph was plainly a cipher, five-letter groups that meant nothing at first glance.

   Analysts worked through the intercepted ciphers one by one, hoping for a single careless repetition.

3. 3
   nobodynouncountable

   A person or thing of no importance.

   The board treated the new chairman as a mere cipher who signed whatever was put in front of him.

   With the founder running everything, the other directors were little more than ciphers.

   UsageMost often a mere cipher or little more than a cipher.

   Similarnobody, nonentity, zero, nothing, also-ran

   Note

   The picture behind it is the zero, a figure that holds a place but adds nothing of its own. Washington Irving, spelling it cypher in 1824, sets a man who was a mere cypher in one company against the same man as lord of the ascendant in another. Source

   Checked 2 Nov 2026 · 4 facts

   • The figurative sense is connected with cipher meaning zero. en.wiktionary.org
   • Zero can hold a numerical place while having no value of its own. mathshistory.st-andrews.ac.uk
   • The Irving passage dates from the 1824 publication of Tales of a Traveller. archive.org
   • Irving uses cypher and contrasts the same man's insignificance in one company with his dominance in another, in The Club of Queer Fellows. en.wiktionary.org
4. 4
   verbintransitive

   To turn written messages into code or cipher.

   Agents in the field were taught to cipher quickly, even by flashlight.

   He ciphered late into the night, turning each report into blocks of numbers.

   Similarencode, encrypt

   Oppositedecode, decrypt

5. 5
   letter designnouncountable

   A design formed by combining or interweaving letters, such as the initials of a name.

   The silver cups were engraved with the family's cipher, an interlaced G and R.

   The old mailbox still carries the royal cipher of a long-dead king.

   UsageMonogram is the everyday word for interlaced initials; cipher is usual in the royal cipher.

   Similarmonogram

   Note

   This cipher nearly always belongs to someone: a painter's cipher, an engraver's cipher, a family's cipher engraved on its silver.

6. 6
   rap sessionnounslangcountable

   A hip-hop jam session.

   After the show, a few of us jumped into a cipher in the parking lot and freestyled until security showed up.

   She held her own in the cipher, trading verses with rappers twice her age.

   UsageSpoken of as a place: in the cipher, jump into a cipher.

   Note

   It is something you join rather than a show you watch, so who gets let in is part of the point, as when Akua Naru raps about being told women are kept out of the circle, and answering by performing alone.

7. 7
   smoking circlenounslangcountable

   The route, usually a circle, that shared cannabis follows as it is passed around a group; also, a session of smoking cannabis.

   Don't hold up the cipher, man. Puff and pass.

   A few friends lit up and started a cipher on the roof after work.

   Similarrotation

   Note

   A Tribe Called Quest's "Midnight" (1993) already has police breaking up a smokers' cipher and destroying the blunt. The word pictures the circle a shared joint or blunt travels round, one turn each, and smokers also call that circle the rotation. It comes from the same hip-hop setting as the freestyle session.

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