The Free On-line Dictionary of Computing (30 December 2018):

Intel 80386SX
386SX

    A lower-speed version of the Intel 80386.  It
   uses a 16-bit data bus instead of a 32-bit data bus.  It has a
   24-bit address bus.  It is faster than the 286, and more
   importantly, like the full-size 386, provides more flexibility
   in running existing DOS applications.  Intel's version runs at
   16 MHz, while AMD's can run at up to 33 MHz.  It comes in a
   PFP package.

   (2003-07-05)