Perhaps a "digital money". Who said we can't spend bitcoin like money does? We definitely can. The only difference fiat money and bitcoin are facing is that fiat money has physical existence while bitcoin doesn't have. If money can be used to pay bills, pizza, etc. Bitcoin can also do the same through crypto local wallets.
It was also alternative paymeny method next to fiat money.
And according to Forbes,
-A means of exchange
-A store of wealth
-A unit of account
And bitcoin does this all characteristics, too, isn't?
We can argue what is the definition of money or currency. But we agreed that bitcoin can be used as a medium of exchange, then it's a money. Whatever that can be used and agreed by both parties as a medium of exchange, just like bitcoin being used as a means of payment across the world or at least by people in this forum or citizens in Japan to buy goods or pay the bills. One thing that bitcoin need is more countries stated bitcoin accepted as means of payment, bitcoin is one step further after PayPal enable users to spend bitcoin on 26Million merchants.