cipher
noun
a secret method of writing or recording data, such as by substituting or adding letters or numbers, using specially formed symbols, or the like; code.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Mr. Dosson, it may further be noted, was a person of the simplest composition, a character as cipherable as a sum of two figures.
From The Reverberator by Henry James