What term describes the act of borrowing money that must be repaid with interest?

The term that describes the act of borrowing money that must be repaid with interest is "loan." A loan is a financial arrangement where one party lends money to another with the expectation that it will be paid back over time, typically along with interest. This interest is the cost of borrowing the money, allowing the lender to earn a return on their investment.

In contrast, finance is a broader term that encompasses the management of money, including borrowing, lending, investing, and budgeting, but does not specifically refer to the act of borrowing itself. A grant, on the other hand, is a one-time sum of money given for a specific purpose that does not need to be repaid, making it distinct from loans. Equity represents ownership in a company, typically in the form of stocks, and does not involve borrowing money. Therefore, the most accurate term for borrowing money that must be repaid with interest is "loan."