You definitely have to define bitcoin as money. It has all the required features, and it is used in exchanges.
That's not a good reason to classify bitcoin as money. Bitcoin has additional features that money lacks. We don't have a word for it yet but what ever Bitcoin is, money is a subset of that.
We have words.
Compared to paper fiat:
Possible to transfer over the net.

Can be backed up.

You need a computer

What kind of properties does bitcoin have that makes it not money?