Over the years, I’ve seen it spelled both ways. For example, that new movie with Liam Neeson in it has the e in it, but my Crayola crayon has the a.
Yes, I have crayons. I’m not on trial here!
Anyway, remember that post I did a while back on British vs. American spelling? Yeah, this is another one of those, with the US preferring the a and the British preferring the e. If you don’t feel like clicking on the link, I’ll inform you that most of those words (i.e. favor and favour) were changed when Noah Webster, in his desire to have distinct American spellings, came out with a dictionary in 1828 that took out what he believed were extraneous letters. I mean, look at that u up there, just hanging around, letting o and r carry it through the rest of the word.
However, gray/grey is different. For one, its “proper” spelling has always waffled back and forth in both major English speaking countries. Webster preferred gray, so that stuck in the US. Across the sea, the British didn’t have a confirmed spelling for it until last century, although grey was always the more popular one.
Both spellings have the same etymological line, the Old English graeg and the Proto Germanic grisja (which also found its way into non Germanic languages). It’s unknown when the different spellings showed up, but it’s possible that it’s always been that way. Grammar and spelling are relatively new developments in terms of language. It’s not impossible to assume that two spellings remained even after the rules became solidified.
So…which spelling do you use?
PS. Greyhounds aren’t named for being grey hounds. Just an interesting bit I discovered.