Dear Geist,

Can you tell me where the expression “It’s not my pigeon” comes from? I overheard someone say it recently, and it brought back my childhood half a century ago.

—Tuck, Cyberspace

Dear Theresa,

According to World Wide Words—a must-browse for word nerds—pigeon in the sense you describe refers to the speaker’s interest, concern, area of expertise or responsibility. An example: “Do what you want about that committee—it’s not my pigeon.” The term has nothing to do with today’s pigeons, those cheerful, determined, indestructible city birds that are actually descended from rock doves. And it isn’t spelled that way either. It comes from pidgin, a simplified hybrid language developed by people who do business with each other but don’t know each other’s languages. The pidgin, a third language, may take the form of talk, gestures, sounds and/or body language. The word pidgin comes from a Chinese pronunciation of the English word business. Pidgin and pigeon are similar enough that over time, other speakers and writers picked them up and used them interchangeably.

—The Editors