Gabrielle in Beloit, Michigan, asks why the closure on trousers is called a fly when the word more commonly names an insect or the act of moving through the air. In clothing, fly first meant the overlapping cloth flap that covers the opening, not the zipper itself. That sense is related to uses such as a tent fly, a protective flap or covering at an entrance. Button flies came before zipper flies, since zippers were a later addition to garments. This is part of a complete episode.
Transcript of “Tent Flies and Trouser Flies Share the Same Flap Sense”
Hello, you have A Way with Words.
Hi, this is Gabrielle Motika. How are you doing?
Hi, Gabrielle. Where are you?
I am in Beloit, Wisconsin.
Beloit.
Beloit.
One of the funnest town names to say, Beloit.
Beloit.
That’s the sound of a faucet dripping in the other room.
Yeah, I always heard a quarter in a toilet.
Beloit.
Well, what’s going on, Gabrielle?
Well, I am the mother of a nine-year-old, a five-year-old, and an almost two-year-old.
And as such, I have the lovely job of needing to teach the English language to complete blank slates.
The other day I was looking at my five-year-old, who is my word lawyer.
If there is a way that he can talk his way out of something, he will.
So I have to think very carefully about everything I say to him.
Oh, boy.
And as a five-year-old is, his pants are not completely closed.
And my first thought was, zip up your fly.
And I realized they only know the insect or the action.
How do I explain and where does this come from?
The word fly to mean a closure of your pants.
Oh, boy.
Did he do it, though?
Because I have a word lawyer at home myself.
No, I said, zip up your pants, buddy.
And he did.
But there are colloquialisms that we use every day and don’t even think about teaching our children.
And my oldest is on the spectrum.
So everything is very literal with him.
My middle one started speaking at four months old,
And everything with language is a game for him.
Wow, four months.
Yeah.
And you sleep when?
When the two-year-old goes to bed with me.
Okay.
Let me ask you this, because this word confused me for a long time.
Do you ever go camping?
I used to when I was growing up, and I did see that there’s tent flies.
That was my question.
Which, again, is a little bit of an unusual word.
Right, right.
But it’s the same idea there.
On a tent, you have a fly, which is the flap in front, right?
Mm—
And this is the thing that I think surprises a lot of people when they dig into this.
The word fly in this case doesn’t refer to the zipper itself.
Nor the opening.
Nor the opening. It refers to that flap over the zipper. That’s a fly, just like a fly on a tent.
Which is why you have button fly jeans.
Exactly.
Right.
Exactly.
Yeah. So it has to do with that flap and the idea of fly being an old word for flap.
Okay. I was wondering about that. I put it out to my friends who have a rather diverse set of interests and skills,
Including reenacting.
And one of my friends said, well, maybe it has to do with cod pieces.
And I’m like, how do you get cod pieces from fly?
They’re thinking about fishing?
I don’t know.
Yeah, I don’t know.
Yeah, well, it does have to do with the history of men’s fashion
And the fact that back in the day you did have a flap that went over that part of the anatomy.
Okay.
So it’s the flying one piece of cloth over another.
Right, right, kind of flapping like a wing does.
Well, but also looking a lot like folded wings, whether on an actual housefly or on a bird.
They have this interesting way of tucking in and covering a space, right?
So it kind of came from people observing nature around them.
It’s not 100% clear that that’s the origin.
How they talked about it.
It’s not 100% clear, but clearly there’s something happening here between the word fly,
The idea of flap, which is also wing-related.
Certainly there’s something happening here.
So that’s pretty much it.
And you mentioned button flap.
Originally it was buttons there, and the zippers only came later.
I only recently learned that zipper originally referred to boots,
Like galoshes that had zippers on them.
I did not know that.
And zippers only were added to clothing later on.
Thank you very much, Gabrielle, for your call.
We really appreciate it.
And good luck teaching you.
Well, thank you for answering my question.
Good luck filling those blank slates.
Thanks.
You have a lovely day.
You too.
Bye-bye.
Bye.
I do like the idea of the word lawyer, children.
I think I’ve told you this once.
My son still does this, but I’ll say, stop jumping on the bed.
He’s like, I’m not jumping.
I’m boinging.
I’m like, oh, don’t do that.
You know what I meant.
I’m not throwing.
I’m tossing.
