Source : WordNet®

FSB
     n 1: the internal counterintelligence agency of the Russian
          Federation and successor to the Soviet KGB; formerly led
          by Vladimir Putin [syn: {Federal Security Bureau}, {Federal
          Security Service}]
     2: a federally chartered savings bank [syn: {federal savings
        bank}]

Source : Free On-Line Dictionary of Computing

FSB
     
        {front side bus}