Define cost. cost synonyms, cost pronunciation, cost translation, English dictionary definition of cost. n. 1. An amount paid or required in payment for a purchase; a price. View real-time stock prices and stock quotes for a full financial overview. COST definition: 1. the amount of money needed to buy, do, or make something: 2. the amount of money needed for a…. Learn more. Cost is the value of money that has been used up to produce something or deliver a service, and hence is not available for use anymore. In business, the cost may be one of acquisition, in which case the amount of money expended to acquire it is counted as cost. The meaning of COST is the amount or equivalent paid or charged for something : price. How to use cost in a sentence. Find the latest Costco Wholesale Corporation (COST) stock quote, history, news and other vital information to help you with your stock trading and investing. Cost is the expenditure required to create and sell products and services, or to acquire assets. When sold or consumed, a cost is charged to expense. COST funds science & technology research networks known as COST Actions that connect researchers & innovators across Europe & beyond. Official website for Costsco Wholesale. Shop by departments, or search for specific item(s). Read this article to learn about what cost is in accounting, how it works, and how it is calculated. Also, look at some examples of cost.