clean one's clock

In 2004, I asked Merriam-Webster the following question. Associate Editor, Kory L. Stamper, replied as follows.

Q: Your Collegiate Dictionary defines the phrase, “clean one’s clock,” as “to beat one badly in a fight or competition.” But “clock” is somewhat imprecise. Does it mean to beat another intellectually or physically, or both? Perhaps it’s just a stock word, symbolizing all these things? If so, can you tell me the origin of the phrase?

A: Like many phrases, “clean one’s clock” originated in spoken English, so it is nearly impossible to come up with a definitive origin for the phrase. We have evidence of “clock” being used of someone’s head or face as far back as 1908, but this use doesn’t have any documented connection to “clean one’s clock.” Our earliest citation for “clean one’s clock” is from 1959, while the heyday of the “face” sense of “clock” was the 1920s and 30s. It’s certainly possible there’s a connection, but without further written evidence, we can’t positively say one way or another.

As for what “clock” means in the current phrase, it’s difficult to tease it apart from the meaning of “clean,” which is why the phrase “clean one’s clock” is entered as opposed to the separate elements “clean” and “clock.” Our citational evidence shows that it’s used for the physical (Language Arts, Vol. 66, No. 3, March 1989):

“Defeated players ring the Champ squares, egging on those still in the game. . . . “Spike him one.” “Clean his clock.”

and for the abstract (Time, Vol. 130, No. 23, December 7, 1987):

“We have come down on the side of it not being worth what it costs right now,” says Runkle. “But we could be wrong. Honda could come in here and clean our clock with four-wheel steering.”