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

byte-code

    A binary file containing an
   executable program, consisting of a sequence of (op code,
   data) pairs.

   Byte-code op codes are most often fixed size bit patterns, but
   can be variable size.  The data portion consists of zero or more
   bits whose format typically depends on the op code.

   A byte-code program is interpreted by a byte-code
   interpreter.  The advantage of this technique compared with
   outputing machine code for some particular processor is that
   the same byte-code can be executed on any processor on which
   the byte-code interpreter runs.  The byte-code may be compiled
   to machine code ("native code") for speed of execution but
   this usually requires significantly greater effort for each
   new taraget architecture than simply porting the interpreter.

   For example, Java is compiled to byte-code which runs on the
   Java Virtual Machine.

   (2006-05-29)