noun

1. the symbol 0, indicating a value of zero
2. a person or thing of no importance or value
3. 1. a system of secret writing based on a key, or set of predetermined rules or symbols
   2. a message in such writing
   3. the key to such a system
4. an intricate weaving together of letters, as a monogram
5. an Arabic numeral

Etymology: ME cifre < OFr cyfre < ML cifra < Ar ṣifr, ṣefr, a cipher, nothing < ṣafara, to be empty

intransitive verb, transitive verb

1. to solve (an arithmetic problem)
2. to write in or with a cipher ()