You sway as you swing your scythe: swoop, swish, slash. And again and again. Each sweep makes a swath: a track of cut stalks as wide as your blade and as broad as your swing.
And then, oops, you slip! Your scythe cuts your skin. You stop and grab a bandage, a big piece of cloth, and wind the swathe around the wound until it is swathed.
Most of the time, swath – also spelled swathe at times, mainly in England – and swathe are used figuratively. We know “cuts a wide swath,” for instance. We think of a swath as a sweeping span of terrain, typically lately cleared by action. The sw- plays well with other words suggesting curving motion; they make a nice set, even though they’re not all related. But then there’s this other swathe just to confuse things: the one that is not an exposed patch but a wrapping or cloth for one. You could lay down a swathe on a swath, even.
Is that how we got here? That you make a swath and then you ease it with e, laying that last letter on so you can lay a swathe on top?
Nah. The words are not originally related. It’s like cleave and cleave. Except that the cleave words were at least distinct in Old English. The swath(e) ones were already both written as swæþ by the time of Beowulf. But, on the other hand, they sound different. The scything one, which rhymes with moth, comes from a root to do with swinging – it may or may not be related to swing – while the wrapping one, which rhymes with lathe or with the first part of rather, comes from a root to do with bandages – and is also the root of swaddle.
So how do you remember which is which? I tend to think of the one without e as bare, and the one with e as dressed. But remember that readers in general are likely to be less familiar with the swaddling one. And while you’re at it, remember that the bare-patch or open-tract one shows up most often in tired clichés. Consider cutting it.