Noah Webster's New International Dictionary of the English Language

1. (n.) A numerical character zero; also a cryptographic system or key where each letter or digit replaces another.

2. (n.) One who, or that which, has no weight or influence.

3. (n.) A character in general, as a figure or letter.

4. (n.) 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. (n.) A private alphabet, system of characters, or other mode of writing, contrived for the safe transmission of secrets; also, a writing in such characters.

6. (a.) of the nature of a cipher; of no weight or influence.

7. (v. i.) To use figures in a mathematical process; to do sums in arithmetic.

8. (v. t.) To write in occult characters.

9. (v. t.) To get by ciphering; as, to cipher out the answer.

10. (v. t.) To decipher.

11. (v. t.) To designate by characters.