to commit money to a business opportunity to make a profit
General Motors (GM) will invest a whopping $14 billion in China over the next five years.
to commit resources to a company, project, or plan etc
Managers invest a large amount of human capital in the firms that employ them.
to pay money into an interest-bearing bank account; to buy bonds, to buy shares, or to make some other financial commitment in the hope of making money through interest payments or dividends (=money paid to shareholders if a company makes a profit)
The idea is for grandparents to invest money when the child is very young.