If you liquidate something, you get rid of it. When a huge retailer has to close all of its stores, it liquidates everything, meaning the inventory and even the shelves and display cases are sold to bargain-hunters, to raise money for the company to pay its debts.
Liquidate comes from the Latin liquidare, meaning “to melt,” or “to clarify.” A recipe might ask you to liquefy the butter, not liquidate it, because liquidate has to do with assets. To liquidate is to convert stocks or goods into cash by selling them, to finish business neatly, and to clear debts. If you liquidate your old baseball card collection, you will have money to put in your college fund.