I’ve heard that and I have no doubt that is it too. Though I don’t know if the context of Thedas itself changes the way it is used, so I kind of left it alone as is. If that makes sense?
My speculative info about it, would be that it does definitely mean Rat and probably means Tevinter saw the elves as pests that Thedas needed to be rid of. Dehumanizing them and giving them reason to “exterminate” and cage the Ancient Elves.