Leverage
buying with borrowed money: it multiplies both the profit and the disaster
In more detail
The ratio of other people's money to your own in a deal. To buy with twenty of your own and eighty borrowed is to work with leverage: both the profit and the loss on your money are multiplied several times over.
It was invented not for the risk but for the return: if the business you bought brings in more than the debt costs, the difference goes to whoever put in the smaller part.
Where it appears in the course
In the academy “Leverage” is not a definition but an operation: you post it yourself and watch what it does to the balance sheet.