Knuckle Down (Phrase) – Meaning & Origin


If someone says they’re going to “knuckle down,” that means they are going to get serious.

Example: The gutters on Baldwin’s house are full of leaves, so they do not drain properly. He knows they need to be cleaned, but that task has been delayed because of the cold weather. However, it has warmed up recently, so he intends to knuckle down and get the job done. (In other words, he is going to make a serious effort to clean the gutters.)

1. Buckle down
2. Pull out all the stops
3. Time to get serious

The Phrase - Knuckle Down
Kids playing marbles, with one of them having his knuckles down.

What Is The Origin Of “Knuckle Down”?

The phrase “knuckle down” might originate from the game of marbles. How so? Let’s take a brief look at the game to see why that is:

In marbles, aiming and precision is key. Before the game begins, a circle is made on the ground and some marbles are put inside of it. Players then try to hit the marbles out of the circle by flicking a “shooter marble” at them. When a player is getting ready to take their shot, they make a fist with their hand and then put their knuckles down to the ground. Once in this position, there is a small opening on the index finger that the marble rests on, and the thumb is positioned just behind that, ready to flick forward. This “knuckling down” that happens in marbles is possibly where the phrase originated.

​Anyway, this phrase goes back to at least the 18th century. It’s written in a book called A New General English Dictionary; Perculiarly calculated for the Use and Improvement Of such as are unacquainted with the Learned Languages, first worked on by Thomas Dyche, then later, finished by William Pardon around the year 1740. For context, there is a part from the book that explains what knuckle down means, and it says:

“To stoop, bend, yield, comply with, or submit to; and is a particular phrase used by lads, at a play called taw, wherein they frequently say, Knuckle down to your taw, or fix your hand exactly in the place where your marble lies.”

In the quote, a “taw” refers to a marble.

Example Sentences

Here is an example of this phrase in a sentence:

  • Ray concluded that he needed to knuckle down to have a chance at winning the next swimming race at his high school.

Similar Examples:

  • I’m done messing around, it’s time to get serious!
  • My kids like to play and have fun, however when homework time arrives, they know to buckle down and pay attention.

Note: The origin of quite a few common idioms cannot be said with a certainty, so if that happens, what you might see listed on the page is a theory about its origin.

Anyway, for more phrases and sayings, use the menu at the top to find them. There are tons on here to explore!