1 derogatory A theatre, (later) especially one in which musicals, variety acts, or similar shows are performed. Also occasionally: a show, an exhibition. Now somewhat rare and historical (US in later use).
2 historical A shop containing a prominent display of goods for sale; specifically (chiefly depreciative) a shop displaying fixed-price clothes, shoes, etc., which are made to measure in a separate workshop. Compare "slop-shop".
Late 18th century. From show + shop.