Knock Yourself Out – Idiom, Origin and Meaning

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Candace Osmond

Candace Osmond studied Advanced Writing & Editing Essentials at MHC. She’s been an International and USA TODAY Bestselling Author for over a decade. And she’s worked as an Editor for several mid-sized publications. Candace has a keen eye for content editing and a high degree of expertise in Fiction.

If you want to master the English language, you have to know idioms and understand their origins and meaning. “Knock yourself out” is a pretty common idiom we use in English, but let’s take a peek at where it came from and why we use it.

Knock Yourself Out Meaning Explained

The idiomatic expression “knock yourself out” is a fairly popular phrase you’ll see and hear used when someone is giving permission or encouragement to do something. It’s mostly used in an informal way and sometimes with a bit of humor or sarcasm, giving someone the green light to do as they please.

“Can I have some of your chips?” I asked. “Knock yourself out,” he replied, handing the bowl to me.

Origin of Knock Yourself Out

There’s actually no definitive origin to pinpoint on this phrase. But it’s said that it derived from the concept of boxing. When an opponent is knocked out, it means there was a victory or some kind of success achieved through physical effort.

Others state that it came from the idea of simply exerting yourself to the point of exhaustion or collapse in order to do something, sort of like firing on all cylinders. It eventually became a laughable phrase to suggest someone can do something as much or as hard as they wish.

Is Knock Yourself Out an Idiom?

Yes, absolutely. “Knock yourself out” is classified as an idiom in the English language since idioms are words and phrases we use in an ironic or figurative way, and knocking yourself out should never be taken literally.

Synonyms for Knock Yourself Out

There are tons of other ways to say “knock yourself out” if the expression doesn’t quite fit in the context or vibe you’re dealing with.

  • Go ahead
  • Be my guest
  • Go for it
  • To the hilt
  • Fill your boots
  • Help yourself
  • Enjoy yourself
  • Feel free
  • Dive in

Knock Yourself Out Examples in a Sentence

Sometimes it helps to see words and phrases used in a full sentence in order to get the complete effect of their meaning.

  • If you want to try a bite of the dessert I made, knock yourself out!
  • “Can I borrow your bike?” she asked me. “Sure, knock yourself out,” I told her.
  • Do you want to rearrange all our furniture? Knock yourself out, as long as I don’t have to do it.
  • When I told my husband I planned to paint the living room while he was away, he just sighed and laughed as he said, “Knock yourself out.”
  • Dave was hesitant to use the office printer for personal use, but his co-worker assured him, “Knock yourself out; no one will mind.”

Knock Yourself Out With Grammar!

See? It’s easy to learn new words and phrases with tips like mine! I love idioms. I think they can add such character to our vocabulary, whether written or spoken. So, try using “knock yourself” out and see how it goes!