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.
Folks, let's remember rule number one of JavaRanch: Be Nice.
I don't think it's an English question; the term has a specific technical meaning. It refers to classes that are still part of a library or application, but which are kept around only for compatibility purposes, not for use in new code. You shouldn't use legacy classes in your own code if you could possibly help it, since by definition there are always superior replacements available.