Well it's simpler to look up what autonomy means in Spain rather than look for contradictory definitions in dictionaries. In fact, it means different things for different autonomous communities, each of which has its own constitution. Spain is, in effect, more of a federation than anything. Whichever community you're talking about, the degree of autonomy is considerable. The Basque Country and Catalonia characterise themselves as nationalities and are, in most regards, the most "autonomous" of the regions. We can all read wiki. And I don't see what it has to do with Brexit right now, frankly.