1New reasoning; a new philosophy or style of reasoning; a fresh theory or approach.
2 historical Specifically. Also with capital initials. The reformed foreign policy of the Soviet Union from 1987 until its dissolution in 1991, promoted by Mikhail Gorbachev and characterized by a non-confrontational openness and a willingness to enter into arms control negotiations with the West. Compare "glasnost", "perestroika".
Mid 19th century; earliest use found in William Shedd (1820–1894). From new + thinking.