Source : Free On-Line Dictionary of Computing

16 bit
     
         Using {words} containing sixteen
        {bits}.  This adjective often refers to the number of bits
        used internally by a computer's {CPU}.  E.g. "The {Intel 8086}
        is a sixteen bit processor".  Its external {data bus} or
        {address bus} may be narrower.  The term may also refer to the
        size of an instruction in the computer's {instruction set} or
        to any other item of data.
     
        See also {16-bit application}.
     
        (1996-05-13)