Collins English-English Dictionary

cipher ['saɪfə]

1. 1. n a method of secret writing using substitution or transposition of letters according to a key

2. 2. n a secret message

3. 3. n the key to a secret message

4. 4. n an obsolete name for zero

5. 5. n any of the Arabic numerals (0, 1, 2, 3, etc, to 9) or the Arabic system of numbering as a whole

6. 6. n a person or thing of no importance; nonentity

7. 7. n a design consisting of interwoven letters; monogram

8. 8. n [music] a defect in an organ resulting in the continuous sounding of a pipe, the key of which has not been depressed

9. 9. vb to put (a message) into secret writing

10. 10. vi. [intr] (of an organ pipe) to sound without having the appropriate key depressed

11. 11. vi. [rare] to perform (a calculation) arithmetically

12. 12. vi. [Etymology] C14: from Old French cifre zero, from Medieval Latin cifra, from Arabic sifr zero, empty