Dear Geist,

What is the difference between autopsy and postmortem? The two seem to be used interchangeably, and not just in cop shows, so why use one or the other?

—Not checking out soon, Richmond BC

Dear Not Checking,

According to Brian Garner, author of Garner’s Modern American Usage, the two terms are equivalent; autopsy is used slightly more in American English and postmortem in British English usage. Put another way, people use the one they’re used to. Garner notes that autopsy as a verb dates back to the late nineteenth century, but “wasn’t recorded in the dictionaries until much later.” Who knows why?

—The Editors