CLOSED SHOP

{n. phr.} 1. A plant or factory that employs only union workers. * /Our firm has been fighting the closed shop policy for many years now./ 2. A profession or line of work dominated by followers of a certain mode of thinking and behaving that does not tolerate differing views or ideas. * /Certain groups of psychologists, historians, and linguists often behave with a closed-shop mentality./ Contrast: OPEN SHOP.