Cranston said a few posts up that Enterprise botched things up by having the term "Romulan" originate with the Romulans.
To be sure, it originated with the Vulcans. In ENT "Minefield", Hoshi Sato distinctly heard the adversaries say "Rumalin", but T'Pol corrected her that they should properly be called Romulan instead. So clearly, Rumalin is the native name for their star empire (although not necessarily for their species or home planet), while Romulan is how Vulcans want to call them, at least when speaking English.
Perhaps "being raised by beasts" is something the Vulcans want to associate with their lost brethren, and it thus is a nice coincidence that the word Rumalin sounds a bit like the common human term for "raised by wolves". The Vulcans exploit this coincidence when speaking English, even if the native Vulcan word for "raised by wolves" (the one that, say, Spock actually says before the UT kicks in) is in fact Harunnaru.
It might be worth noting that the Romulans are self-made men. They left their home and invented an all-new culture for themselves, supposedly in a star system that did not come with any pre-existing names. Their proper names thus would be likely to have
meaning, instead of just being random sounds eroded to meaninglessness by tens of thousands of years of history. Diane Duane's Rihannsu call themselves that because the word has a meaning: in English, they would be calling themselves the Declared. "Rumalin" is no doubt another meaning-laden word in the Romulan language, probably translatable to an English term but instead perverted to "Romulan" by a quirk of history.
...Indeed, perhaps the direct translation of Rumalin would reveal too much to the Earthlings, which is why T'Pol quickly steps in with her insistence that the proper name is something else again...
Timo Saloniemi
-- but it was so much more direct and sensible before Enterprise mucked with it.
