To rent something is to pay money to use it, live in it, or borrow it. If you're not sure which musical instrument you'll stick with and enjoy playing, it's best to rent a few to try out before buying.
Rent is both a verb and a noun for borrowing or leasing something. If you rent an apartment, you pay money to live there, and that money is also rent. You can rent many things, from skates at a roller rink to furniture for the home you rent. You don't own things you rent — you just use them temporarily. A rent is also a rip: "She fell and tore a big rent in one knee of her jeans."