Definitions for FSB
Federal Security Bureau, FSB, Federal Security Service(noun)
the internal counterintelligence agency of the Russian Federation and successor to the Soviet KGB; formerly led by Vladimir Putin
federal savings bank, FSB(noun)
a federally chartered savings bank
(transliterating Russian u0424u0421u0411) The Federal Security Service of the Russian Federation (an intelligence agency of the Russian Federation and one of the main successors of the Soviet Cheka, NKVD, and KGB).