1972 (in reference to a letter of 1969 by Solzhenitsyn), from Russian glasnost "openness to public scrutiny," literally "publicity, fact of being public," ultimately from Old Church Slavonic glasu "voice," from PIE *gal-so-, from root *gal- "to call, shout." First used in a socio-political sense by Lenin; popularized in English after Mikhail Gorbachev used it prominently in a speech of March 11, 1985, accepting the post of general secretary of the CPSU.
The Soviets, it seems, have rediscovered the value of Lenin's dictum that "glasnost," the Russian word for openness or publicity, is a desirable form of conduct. [New York Times news service article, March 1981]