0 an agreement that gives an investor the right to buy a particular number of shares, or other financial assets, at a fixed price and before a fixed date:
1 an agreement in which a company buys a product from another company and has the right to buy more of that product later, but does not have to do so:
2 a financial agreement that gives someone the right to buy property or land within an agreed time and for an agreed amount, especially after they have rented it for a particular amount of time: