noun

• (cryptography) A cryptographic system using an algorithm that converts letters or sequences of bits into ciphertext.
  "a public-key cipher"
• A grouping of three digits in a number, especially when delimited by commas or periods:
  "The probability is 1 in 1,000,000,000,000,000 — a number having five ciphers of zeros."
• (music) A fault in an organ valve which causes a pipe to sound continuously without the key having been pressed.
• (music, slang) A hip-hop jam session.
  "They say no girls in the cipher, so I rock solo"

verb

• (intransitive, regional, dated) To calculate.
  "I never learned much more than how to read and cipher."
• (intransitive) To write in code or cipher.
• (intransitive, music) Of an organ pipe: to sound independent of the organ.
• (obsolete) To decipher.
  "Yea the illiterate that know not how To cipher what is writ in learned bookes, VVill cote my lothſome treſpaſſe in my lookes."