This wisdom began to be written in ciphers and characters and letters bearing the forms of creatures.
Sir W. Raleigh.
4. A combination or interweaving of letters, as the initials of a name; a device; a monogram; as, a painter's cipher, an engraver's cipher, etc. The cut represents the initials N. W.
5. A private alphabet, system of characters, or other mode of writing, contrived for the safe transmission of secrets; also, a writing in such characters.
His father . . . engaged him when he was very young to write all his letters to England in cipher.
Bp. Burnet.
Cipher key, a key to assist in reading writings in cipher.
Ci"pher, a. Of the nature of a cipher; of no weight or influence. "Twelve cipher bishops." Milton.
Ci"pher, v. i. [imp. & p. p. Ciphered (?); p. pr. & vb. n. Ciphering.] To use figures in a mathematical process; to do sums in arithmetic.
"T was certain he could write and cipher too.
Goldsmith.
Ci"pher, v. t. 1. To write in occult characters.
His notes he ciphered with Greek characters.
Hayward.