XML is a language for data storage, not a dictionary format. So you can't expect pyglossary to support any XML whatsoever. However, you can put the XML-file online and post a link to it. Maybe you're lucky.
Suggestions
The Pdf-(2-epub-)2-html-2-stardict tool isn't there, yet. Probably never. The problem is that the nice styling of a PDF puts a lot of extra code in there, that has to be differentiated from the words&definitions. Optically easy, but not code-wise. You could try to get ABBYY Finereader to recognize it and specify the output format as a spreadsheet or CSV-format. However, even ABBYY's output will still have a lot of noise, that you'll have to deal with.
What is the name of the dictionary? Maybe it's already present in a nicer format than PDF.