Eclipse error: indirectly referenced from required .class files?

I got an error in Eclipse. What does this error message means:

The type iglu.ir.TermVector cannot be resolved. It is indirectly referenced from required .class files

Solution 1:

It means: "A class that you use needs another class that is not on the classpath." You should make sure (as Harry Joy suggests) to add the required jar to the classpath.

Solution 2:

This is as likely a matter of Eclipse's getting confused as it is an actual error. I ignored the error and ran the web service whose endpointInterface it complained about, and it ran fine, except for having to deal with the dialog every time I wanted to run it. Just another opaque error that tells me nothing.