Any software included in a package that has little or nothing to do with what you actually want the package for. Examples would include things like installing Avast as part of the download for a pdf reader, which I’ve seen in the past. Much more common today is something like all the excess apps you get when you purchase a new phone. I had to spend a good half-hour combing through privacy settings and deleting over a dozen gem-this and bubble-that apps the last time I got a new phone.