I haven't heard the term before, but I would guess you mean cross-platform compiler.
This is a compiler that can take some source code (like C++) and compile it for different platforms. When you compile some machine-dependant code (basically, anything that makes an executable), the rusulting file will only run on the platform it was compiled for - the file consists of machine code, which can only be understood by a particular processor/system.
A cross-platform compiler (at a guess) could compile some source code into different exeutables for different target platforms - for example, you could write an application in C++ and compile it for windows and macintosh (which you can't generally do).
None of this applies to
Java, as it is not compiled into an executable, but to bytecode, which is then interpreted by the JVM (Java Virtual Machine) on whatever platform you run it on. As long as the system has a JVM (which most do), the file you compiled on any system will run on it.
If that's not what you meant, give a little more detail (eg the full question about cross-compiling).
Grant.