Its not redefining...The price of bitcoin is also unstable if compared to Indian rupees and the price of dollar is also slightly unstable compared to Indian rupees....As like other currency it is also a currency...But its digital currency but not digital money...Digital money are those which are stored in paytm or freecharge etc sites...But its a digital currency...Its just an evolution of technology..
Why not? We never had a decentralized currency before, and provided centralized control over currency is a considerable problem. Yes, Bitcoin is volatile, due to the monetary policy followed by the system. Rupees, Dollars have an inflationary monetary policy, debasing rupees and dollars every year. We can experiment to design a monetary policy to keep the price relatively stable.
By money, I meant tool of exchange. Cowrie shells are money, as they are used to facilitate medium of exchange. Hence bitcoin can also be defined as money.