DuckCorp Dico

Found one definition

1.                 From The Free On-line Dictionary of Computing (19 January 2023):
                   
   
   
                   
                     
   Most Significant Bit
   MSB
      (MSB) Bit n-1 in an n bit binary number, the bit with the
      greatest weight (2^(n-1)).  The first or leftmost bit when the
      number is written in the usual way.
      (1995-07-13)