Madeira

When referring to the autonomous region of Portugal, the word is a proper noun and is always capitalized. It describes a specific geographic location, and as such, it does not have a plural form.

When referring to the fortified wine, the word functions as a mass noun. It describes a specific style of wine characterized by a unique heating process called estufagem. In this context, it is typically used without an article when discussing the liquid in general, or with a partitive (e.g., a glass of Madeira) when referring to a specific serving.