Appointing a dictator for a period of a year in case of emergency is compatible with democracy. Appointing a dictator for life is not. Mainly because the dictator for the period of a year is, after that year, still accountable. Orban, Erdogan, and Maduro are on various stages of the road from democracy to non-democracy. Regarding the Romans another matter is of course that only a small part of the population has any influence on the senate, so it is in fact clearly not a democracy.
If I have to judge what is a democracy, I am going back quite a while to what I learned in high school as the definition of a democracy. "A democracy is a form of government where the three branches of government, the legislative, the executive and the judicial branch are separated and the legislative branch is in the hands of representatives elected by the people."
Democracy is more fundamental than that. It simply means rule by the people. The three branches of government was a later invention, and not all democracies feature it. Political theory surrounding the definition of democracy is more concerned with who has power and how they have it, and has less to do with how it is structured, as much as a US-centric definition may take it to be. Eg parliamentary systems are considered democratic despite a different structure.
That sounds very American though. For example how does the Westminster style system fit into it? While the Prime Minister might be described as the executive, they're actually just the leader of the majority Legislative party.
If I have to judge what is a democracy, I am going back quite a while to what I learned in high school as the definition of a democracy. "A democracy is a form of government where the three branches of government, the legislative, the executive and the judicial branch are separated and the legislative branch is in the hands of representatives elected by the people."