Comparison is not to a set meaning of the word “conservative.” Conserve means to retain, save, etc. The Iranians would be conserving the Theocracy or more remotely the Monarchy. American conservatives would be conserving Constitutional Government, our founding and precariously continuing system. An Iranian advocating American style Constitutional government would be a total Radical. Liberal has a meaning with ideological components. “Conservative” has historical components relative to its society. It is not like a name. It is not “George” or “Phyllis” that would refer to one discrete system in one particular time and place.
It is, as the so-called American 'main-sleaze' media employ it. To them, "conservative" anywhere in the world equates to American "conservatives." You might as well call any self-loading rifle an 'assault weapon'...