First part of your definition is "a system". I'm pretty sure that bitcoin does not fail that part of the definition.
The next part of your definition is "of money". There is a lot of debate about whether bitcoin passes that test because people seem to have a difficult time agreeing on a definition of the word "money". In the jurisdiction of the U.S. federal government a federal judge has declared that bitcoin is a Money. Perhaps he is mistaken, perhaps not. This is why this topic is being discussed again for the billionth time and why this discussion won't resolve anything any more than any of the other discussions. Until there is a definition of "money" that everyone can agree with, people won't be able to agree on whether or not Bitcoin is Money.
The next part of your definition is "in general use". I think we can all agree on the fact that bitcoin is "in use", so now we have to agree on a definition of "in general use". Good luck with that one.
And the final part of your definition is "in a particual country". That would seem to indicate that it doesn't have to be a "money in general use" throughout the entire globe. If even one country decides that it is a "money", and it is in "general use" in that one country, then it is a "currency".
What up with your unhealthy desire to call Bitcoin a currency?
Do you realize that there are hundreds of economic theories on how currencies work.
There are old-school economic predictions, concepts and market models - all relying on the that definition.
Fundamental quality of currency is that it is issued by single authority (country).
Bitcoin is not centrally issued - why would you want to stick together with a bunch of regular currencies?
If anything, there should be a new definition.
Let's call it Dannyrency - it will be like a regular currency just not centrally issued.