Malvoisie (or Malvasier) is another spelling for Malvasia. The name is used mainly in France for various unrelated grape varieties. They are mainly synonyms:
See also in detail under Malvasia, where about 100 grape variety names with this name rope in the main name or in synonym are listed.
The glossary is a monumental achievement and one of the most important contributions to wine knowledge. Of all the encyclopaedias I use on the subject of wine, it is by far the most important. That was the case ten years ago and it hasn't changed since.Andreas Essl