v. phr. 1. To shut a store at the end of a day's business, also, to end a business. The grocer closes up shop at 5 o'clock. After 15 years in business at the same spot, the garage closed up shop. 2. informal To stop some activity; finish what you are doing. After camping out for two weeks, the scouts took down their tents and closed up shop. The committee finished its business and closed up shop.
Compare: CALL IT A DAY.