A place of business or employment; a factory, office, or other business establishment. A shop may be open, closed, or union. closed shop. A shop where working conditions are covered by a collective bargaining agreement between management and a labor union. Union membership is required as a condition of working there. open shop. A shop where union membership is not a precondition of employment. Union members and nonunion members may work side by side. union shop. A shop in which all workers ar...