This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
What is the context in which you heard that term? I've heard of "precompiling" before, but it's not a common concept in Java.
I remember this from Microsoft Visual C++. Compiling C++ code can take a long time. To make the compilation process quicker, Visual C++ would precompile C++ header files for you - so it would compile parts of the program in advance, so that everytime you change something, it would not have to compile everything from scratch.
Maybe some IDEs for Java do a similar kind of thing, and that's where you heard of it?