"Peter Out"

Stupid Question ™
June 12, 2003
By John Ruch
© 2003

Q: What’s the origin of the term “peter out”?
—Ron Summer


A: It is completely, utterly unknown why “petering out” means “fading away” or “dwindling” (or, in a more recent usage, “being squandered away”).

But I certainly have my own favorite theory.

We have a pretty good idea of where the phrase came from. It popped up in Californian mining slang in the 1840s and usually referred to a gold mine running out of the shiny stuff.

But tracing any origin is difficult because “peter” has a wild and bizarre variety of meanings, from an imitative bird cry to “penis” to the familiar Biblical name (the start of it all).

Speaking of “peter” and mines, you may recall that the Biblical Peter was actually called Simon. Jesus, in a typically symbolic mood, gave him the name “Petros” for reasons scholars still debate. “Petros” is the Greek translation of an Aramaic word meaning “stone” or “rock.”

There are, naturally, a couple of loony guesses about “peter out.” One is that it comes from the French peter, meaning “to break wind” (apparently from the sound made by so doing). This is just some goofball checking foreign dictionaries for similar words.

Another idea is that it has to do with the Biblical Peter’s denial of Christ. Methinks that didn’t come up too much in the mines.

Another meaning of “peter” is an abbreviation of “saltpeter” or potassium nitrate, a key ingredient of black powder used in firearms and blasting. Hence, the theory that “petered out” meant you had blasted every last bit of ore out of the mine.

That’s a pretty good idea. Especially because it’s the one I came up with before I looked up what everybody else thinks.

But there are two problems. As far as I can tell, neither “peter” nor “saltpeter” were common terms for the black powder itself, just for the specific ingredient.

Also, this explanation doesn’t address a prior usage of “peter” that throws this whole discussion into a tizzy.

Etymologists have dug up an oddball early-1800s reference to “peter” (by itself, without “out”) meaning “to stop abruptly.” Specifically, it was described as being used as an imperative command meaning to quit or shut up: “Peter that!”

This usage appears to have come before “peter out.” However, it’s a one-hit wonder that doesn’t seem to have gone anywhere. I see no reason to expect that it influenced “peter out.”

Besides, I have less tangible reasons for the hunch that “saltpeter” is right. Of nearly simultaneous origin was “fizzle out,” which came from the sound of fireworks failing to explode—which is to say, of gunpowder sputtering out.