There are 2 main definitions of cipher in English:


Line breaks: ci¦pher
Pronunciation: /ˈsʌɪfə
(also cypher)


1A secret or disguised way of writing; a code: he wrote cryptic notes in a cipher [mass noun]: the information may be given in cipher
More example sentences
  • The enciphering and deciphering of messages in secret code or cipher is called cryptology.
  • Wilkins worked on codes and ciphers, publishing his work in 1641.
  • She was transferred to work on coding and cyphers supervised by Bletchley Park.
1.1Something written in a code: he came across ciphers written on parchment and concealed in a hollow altar pillar
More example sentences
  • An equivalent way of writing the same cipher is shown in the diagram.
  • The English language uses letters with varying frequencies, allowing code-breakers to calculate which ciphers represent which letters.
  • And why are they targeting me with their runes, signs and ciphers?
1.2A key to a code.
More example sentences
  • During this process the cipher secret key is never transmitted on the network.
  • He was forced to reveal his cipher and to contact headquarters with messages written by his captors.
2 dated A zero; a figure 0.
More example sentences
  • From nine years observations, at Cincinnati, it appears that the thermometer falls below cypher twice every winter.
archaic naught
2.1A person of no importance, especially one who does the bidding of others and seems to have no will of their own: journalists are not mere interchangeable ciphers in the propaganda battle
More example sentences
  • Governors have become mere cyphers for the decision-makers - often people with little or no practical experience of the problems faced by prison administrations.
  • Astrid throughout remains a mere cipher, a beautiful woman with a crooked smile whom the narrator met while he was a student.
  • She challenges the assumption that actors are mere ciphers channeling the influence of directors and writers.
nobody, nonentity, nothing, non-person, unimportant person, person of no account
3A monogram: a pair of rock crystal goblets engraved with the cipher of Peter the Great
More example sentences
  • Her Majesty's wishes were that it should be replaced with a Colour bearing the cypher of the Sovereign of the day.
  • Among the drawings are masterpieces by Rex Whistler, whom the Queen Mother also commissioned to design a new royal cipher.
  • The badge of the Wiltshire's was a combination of the Maltese Cross and the Duke of Edinburgh's coronet and cipher.


Back to top  
1 [with object] Put (a message) into secret writing; encode: he left two, as yet uncracked, ciphered messages for posthumous decoding
More example sentences
  • With a black calligraphy pen, each word had been carefully ciphered in a Gothic style.
  • It became a vital tool for the Nazis during World War II who used it to cipher and decipher secret messages.
  • The encryption keys are sent over dedicated links, and the messages ciphered with those keys are transmitted over the Internet.
2 [no object] archaic Do arithmetic.
More example sentences
  • Many people in the community were illiterate, having little need for education beyond simple ciphering, and how to sign one's name.


late Middle English (in the senses 'symbol for zero' and 'Arabic numeral'): from Old French cifre, based on Arabic ṣifr 'zero'.

Definition of cipher in: