Fly as in what birds and aeroplanes do, fly as in the insects, or fly as in “your fly is down”?
edit: I mean the word fly (as in its use in language), not the act of flying!
Fly as in what birds and aeroplanes do, fly as in the insects, or fly as in “your fly is down”?
edit: I mean the word fly (as in its use in language), not the act of flying!
I’m not sure what you’re talking about. Looking up camping tents, the vast majority have the classic pitched rain fly.
But regardless, that style of rain fly is pretty new, so it’s irrelevant to the reason they were named flies in the first place. I doubt it was common for tents to even have zippers when the term rain fly was coined.
Edit: Looking into it further, the term rain fly was coined before the term fly was used to describe the fabric covering the zipper. It looks like calling the fabric covering the zipper a fly came from using fly to describe the fabric covering a tent.