Defining "Monarchy"

As I celebrate the twelfth anniversary of my website, created on this date in 2000, it's worth reflecting on the meaning of the word it's all about.  One problem that monarchists sometimes run into, especially in online discussions, is defining exactly what a "Monarchy" is.  While I regard a hereditary element as normative, there are non-hereditary exceptions (Vatican City, Andorra, Samoa) that have to be acknowledged.  Particularly galling is when republicans want to claim horrible dictatorships such as North Korea (which has now had leaders from three generations of the same family) as "Monarchies."  But the definition at Wikipedia's article on Monarchy, which is much better than it used to be, is about the best I've seen: "A monarchy is a form of government in which sovereignty is actually or nominally embodied in a single individual (the monarch)."  (I might change "actually or nominally" to simply "officially.")  This manages to cover unusual cases such as Vatican City while excluding superficially "hereditary" authoritarian republics.  Since nominally republican regimes like those of Belarus, Syria, and North Korea still claim to embody sovereignty in "the people," they are not monarchies, no matter how absurd that claim is, and monarchists do not have to answer for them.  (Even Nazi Germany never formally repealed the 1919 constitution of the Weimar Republic.)