or Cypher (from the Arabic sifr, devoid of empty), one of the Arabic characters used in computation, and formed thus, 0.

Cipher is also a kind of enigmatic character composed of several letters interwoven; as the initial letters of a person's name. Anciently, merchants and tradesmen not being allowed to bear family arms, in lieu thereof bore their ciphers, or initials of their names, artfully interwoven about a cross. These frequently occur on tombs and other monuments.