“Cipher” comes from an Arabic word that means “zero, empty, or nothing.” The Arabic numerals (1, 2, 3, and so on) are also called ciphers, and a person can cipher a math problem, which means to work it out. 

A cipher can also be a sign or symbol, such as the royal cipher adopted by a monarch, or it can describe characters that have no inherent meaning, but instead have a hidden meaning, such as a code written in a nonsense alphabet. Here’s a beautiful example from Alberto Manguel’s book “A History of Reading”:

At one magical instant in your early childhood, the page of a book—that string of confused, alien ciphers—shivered into meaning. Words spoke to you, gave up their secrets; at that moment, whole universes opened. You became, irrevocably, a reader. 

A cipher can also be a person, often a fictional character, who is a blank slate—and that’s how I used the word when talking with my husband. A cipher has so little personality—is such a nothing—that the readers or viewers can project their own ideas and values onto the character. Here’s an example from Allen Barra’s review of the book “Fab: An Intimate Life of Paul McCartney”:

Sounes' biggest weakness in telling the story is his inability to give us a fresh focus on the other Beatles: John seems beyond his ken, George is a bit of a dim bulb, and Ringo, the bane of all Beatles biographers, is simply a cipher.

Here’s another example from a 2011 article about a Canadian politician whose nickname is Iggy:

Iggy is a cipher. To the extent that the public knows anything about him at all, it's what the Tories have told them. Ask people what they know about him and it's usually the tag lines from Tory ads that come out of their mouths.

So there you go, a cipher can be a sign or a symbol, a coded message, the act of solving a math problem, or a person who is nothing, a placeholder, a mystery, or a blank slate.

The same root also gives us the word “decipher,” which is to work out the meaning of something, often of a code or something that is hard to read in some other way. For example, although many have tried, nobody has been able to decipher the Voynich manuscript, a 15th century illustrated book written on vellum.

Image courtesy of Shutterstock.

Mignon Fogarty is Grammar Girl and the founder of Quick and Dirty Tips. Check out her New York Times best-seller, “Grammar Girl’s Quick and Dirty Tips for Better Writing.”