To close down a business (literally 'lower the sign'); to go out of business or stop operating a shop/company.
地元の古い本屋がついに看板を下ろした。
The local old bookstore finally closed down.
不景気で何軒かの店が看板を下ろした。
Several shops closed down because of the recession.
親の代から続いた会社を、息子さんが事業整理して看板を下ろすことにした。
The son decided to wind up the family business that had been running since his father's generation and close it.