“Authoritarian” is (generally speaking) a word used to describe governments’ usage of violence or other means to either establish or maintain rule over their populace.

So all governments

“Authoritarian” is (generally speaking) a word used to describe governments’ usage of violence or other means to either establish or maintain rule over their populace.

That's just every government. The word is completely meaningless using your definition, you can just say "state" or "government" or "regime".

“A revolution is certainly the most authoritarian thing there is; it is the act whereby one part of the population imposes its will upon the other part by means of rifles, bayonets and cannon — authoritarian means, if such there be at all; and if the victorious party does not want to have fought in vain, it must maintain this rule by means of the terror which its arms inspire in the reactionists. Would the Paris Commune have lasted a single day if it had not made use of this authority of the armed people against the bourgeois? Should we not, on the contrary, reproach it for not having used it freely enough?”

― Frederick Engels