No, it means that the code was compiled to be compatible with the intel 80386 command set. The Gnu c/c++ compiler can compile to 80386, 80586 (pentium/K6/K6-2/K6-3) and i686 (PII/PIII/Celeron/K7/Duron).
But the performance gain is often minimal and compiling for 586 and above may limit your ability to install the software on older machines.