1. Not controlled by others or by outside forces; independent: an autonomous judiciary; an autonomous division of a corporate conglomerate. 2. Independent in mind or judgment; self-directed. In what way is Tibet autonomous?
Well I could be a real smartarse and say – in the same way that Aussie native peoples are Autonomous, but then I realised that’s a stupid answer (even for me) because Australia doesn’t even pretend to give Australian Native peoples much autonomy – the Aussie authorities do not seem to think that the Abo’s (to use the expression that the Aussie public seems to prefer) would be able to make any use of complete autonomy because (a) they’re really too stupid to use it properly, Or (b) they might mis-use it and get some foreign power to help them, and the Aussie Public would not stand for that, now would they?
Anyway, after thinking about all that, I re-thought your selective quotation of the meaning of the word autonomy. I wont re-quote – it’s at the top of the page. Autonomy is very black white thing according to your selective use of dictionary meanings. Let's see if that is really the case.
And, the dictionaries do say what you said they say – but many go on to demonstrate that in usage, autonomy is not a ‘either you have or you don’t,' thing.’
So let’s see now. Googling the word brings up Google’s own definition:
Quote: 1. the right or condition of self-government.
"between the First and Second World Wars, Canada gained greater autonomy from Britain."
Implicit in this statement is the fact that Canada once had no autonomy, but at different stages, most particularly in WW1, autonomy was increased.
The web edition of the Oxford dictionary offers that same point to illustrate usage. (Reference: http://www.oxforddictionaries.com/definition/english/autonomy )
As you see, the suggestion there is that there are ‘degrees’ of autonomy. Let’s see if other sources suggest something similar. The web-based “Free Dictionary” offers these definitions: ( Reference: http://www.thefreedictionary.com/autonomy )
n. pl. au·ton·o·mies
1. The condition or quality of being autonomous; independence.
2. a. Self-government or the right of self-government; self-determination.
b. Self-government with respect to local or internal affairs: granted autonomy to a national minority.
3. A self-governing state, community, or group.
(Highlighting mine) and further down the page:
n, pl -mies
1. (Government, Politics & Diplomacy) the right or state of self-government, esp when limited.
2. (Government, Politics & Diplomacy) a state, community, or individual possessing autonomy.
These two refinements of meaning clearing suggest that autonomy can be (usually is) limited. Or, as stated before, that there can be degrees of autonomy.
In connection with (2) immediately above, its axiomatic that a community or an individual within a modern state has only limited autonomy.
Can I offer an example of limited political Autonomy. From Wikipedia (Reference: http://en.wikipedia.org/wiki/Autonomy ):
In the United States government, autonomy refers to one's own self-governance. One former example of an autonomous jurisdiction into the United States government belong to the Philippine Islands; The Philippine Autonomy Act of 1916 provided the framework for the creation of an autonomous government providing the Filipino people(Filipinos) broader domestic autonomy, though it reserved certain privileges to the United States to protect its sovereign rights and interests. 
The background to this illustration, is that Spain had conquered the island group we call, The Philippines, in the 16 th century. As the Spanish Empire collapsed at the end of the 19 th century, Philippino people moved to set up an independent Republic. The United States (under President Theodore Roosevelt) however fought that move by invading the Philippines and fighting a nasty, vicious war against Philippino freedom fighters. Strangely, I suggest that in the longer term it was this move that eventually brought the Chinese Communist Party to power in China. But back to the point. The Philippine Autonomy Act of 1916 gave a degree of autonomy to a conquered people.
Does that answer your question?