Definitions for "Fortified wine"
is wine to which alcohol has been added to increase the proof to a higher level than the maximum possible from fermentation. The highest proof possible from fermentation alone is 18%.
A class of wines that have been made sweet by interrupting the fermentation process with the addition of a neutral distilled spirit. The spirit kills the yeast before they have finished converting all of the sugar. Port and Sherry are both fortified wines.
A wine to which alcohol has been added, such as Port.