I made a blog post a few weeks ago about redefining what we think about money. It's past 7 days so I am not profiting by sharing things, just trying to contribute to the conversation.
I was shocked to learn how small a percentage hard, physical cash makes up of the total value of assets that there supposed to represent.
My point is, you can't really ask us to define money, as the way it is implemented today is so far removed from it's actual definition.
I was shocked
Of course there is a large separation between paper and digital money. But it goes much further. Have a look at the difference between stocks (representing existing value) and derivatives. Now derivatives do serve some important tasks, but how can the futures market become bigger than its underlying real world value?
All of this wealth is only supported by the believe that it exists somewhere in this world. But once we realise it does not we are in for a big crash. Also notice the scary amount of debt!
Taking my data from (http://money.visualcapitalist.com/worlds-money-markets-one-visualization-2017/)