Mike in Ukiah, California, grew up in the UK, where he often heard the expression to know your onions, meaning “to be knowledgeable about something.” He suspects the phrase is rhyming slang, but It’s most likely one of many metaphorical expressions based on being knowledgeable about products in a marketplace. The earliest seems to be from the 1840s, where to know one’s beans or to know beans about something was used the same way. But there are also the phrases know your apples, know your sweet potatoes, know your vegetables, know your oats, know your bananas, know your fruit, know your eggs, know your cucumbers, know your goods, know your groceries, and know your oil, all of which mean the same thing. There might also be some transference from a French expression, s’occuper de ses oignons, which literally translates as “take care of your onions,” which means “mind your own business.” This is part of a complete episode.
Transcript of “Know Your Onions”
Hello, you have A Way with Words.
Oh, hi. Good morning. My name is Mike Roberts, and I’m from Ukiah, Northern California.
And I have a saying that I’ve heard many times about somebody knowing their onions.
And then after calling you initially, I Googled, and it was from knowing onion rings.
It’s Cockney rhyming slang for things.
So I found that very interesting because I’m from London, born and raised in London.
And then I also found out that rhyming slang started in the 1840s, but there was no record of it being used, no literary record until 1922.
So I was looking for an earlier record.
Yeah. Okay. So let’s break this down. So you’re talking about to know one’s onions, and that means…
Right. To know one’s business.
Yeah. To know what you’re talking about.
Right.
And you knew this from your time in London where you grew up?
Right. I’ve never heard of it after since.
Yeah. It’s not well known in the United States. Although one time it was. You would find it in the United States in the early 1900s.
I’ve got a cocked eyebrow out here. I’m super suspicious of that origin story. I’m not going to discount it because I haven’t seen your source. But generally, Know Your Onions is thought to be just a part of a whole grocery store worth of other expressions that are involved produce.
You could know your beans, know your apples, sweet potatoes, vegetables, eggs, cucumbers, oats, bananas, goods, fruit, groceries, oil.
All of these things have been expressions, all of the means to know what you’re talking about.
And the earliest ones that I know of is to know your beans or to know beans from the 1840s.
Right, right.
There is a French expression from the early 20th century, and it’s about the same age as to know one’s onions, a little newer.
S’occuper de ces oignons.
It translates as to mind your onions,
And it means to mind your own business.
So it’s not quite the same meaning.
So it’s possible if there’s an overlap
Or a transference happening in one direction or the other.
But in any case, we think our prevailing theory
Is to know your onions is simply one of these mini expressions
That means to mind your business.
And it simply has to do with being able to go to the marketplace
And recognize quality produce when you saw it.
And I think that it probably isn’t rhyming slang.
However, I’m open to new evidence.
And if I find new evidence that it is rhyming slang, I will let everyone know.
Okay?
Okay.
Very good.
Well, thank you very much.
All right.
Mike, thank you so much for calling.
We appreciate it.
No, it’s my great, great pleasure to be on the radio as well.
I love your show.
Thank you so very much.
Thanks so much.
Bye-bye.
Okay.
Bye-bye.
