Definition of mid-twentieth in English English dictionary
Usually used before century to indicate the middle part of the 20th Century, which could refer to events in the 1940s, the 1950s or the 1960s. However, in architecture, preservation, and real estate, it is commonly being used to refer to the period after World War II to the mid-1970s
Since the mid-twentieth century, the exchange of Orders has become less personal and more formal and diplomatic.