I've often wondered about the origin of the name Elsweyr (other than the likely explanation that it's a word Bethesda thought looked good when they were making Arena...or possibly they were fed up with creating names, got as far as "that's somewhere else" and decided to reverse it and call it a day).

Particularly because it includes the word weyr which I've been told by various sources is an archaic word for a group of dragons (and never very common because dragons, being fictional, were rarely encountered in large groups). These days it's best known from Anne McCaffery's Pern series, where the dragons and their riders live in 'towns' built into the caldera of extinct volcanoes, called Weyrs (upper case), with each individual dragons cave also called a weyr.

But it also appears in the Dragon Age series where an area of Antiva is labelled 'the weyrs' on the map, and occasionally in other fantasy.

I know in TES lore dragons are mainly associated with Skyrim, because the people there used to worship them, but my understanding is that they could be found all over Tamriel during the first era, so there could potentially have been enough of them in Elsweyr to influence the name. Admittedly I have no idea who or what El would be, it's far too short for a dragon name, but maybe it could be the name someone else gave to a dragon?