We don't have synonyms for closed shop yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are close shop, closed-shop and closed loop.
(n) :
A business or industrial establishment whose employees are required to be labor union members as a precondition to employment.
(n) :
(computing, historical) A facility that runs programs on behalf of others, giving them no oversight over execution but merely returning the output at the end.
(n) :
A business or industrial establishment whose employees are required to be labor union members as a precondition to employment.
(n) :
(computing, historical) A facility that runs programs on behalf of others, giving them no oversight over execution but merely returning the output at the end.