paper airplane n. in aeronautics and aerospace, a flying machine that is strictly theoretical. Editorial Note: The adjectival form paper, referring to something that exists only in print or writing but not as a physical object, is fairly common. Here it connotes an actual toy-sized folded paper plane, carrying with it derogatory and jocular undertones. (source: Double-Tongued Dictionary)
Further reading
Why does the term vegetarian cause so much confusion? Some people assume it means avoiding red meat but still eating chicken. And is there a term for a vegetarian who also eats fish and poultry? Plus, screwball comedies from the 1930s mix slapstick...
Everything Is Tuberculosis: The History and Persistence of Our Deadliest Infection (Bookshop|Amazon) is a powerful and fascinating look at the history of the disease and how its persistence continues to shape global health. The author, John Green...