Madeira here is a strong, usually sweet wine, named after the Portuguese island of Madeira, where it is made. It is a fortified wine: extra alcohol is added, so it is stronger than ordinary table wine and keeps well. People drink it as a dessert wine, in small glasses, and cooks use it in sauces (a Madeira sauce with beef or mushrooms is a classic). The colour runs from gold to dark brown; some bottles are drier, but the famous ones are rich and sweet, a little like a cousin of port. You capitalise it because it is a place name used for the drink. There is also Madeira cake, a plain British sponge that used to be served with a glass of this wine — that is a different entry. In English, if someone says “a glass of Madeira,” they mean the wine, not a trip to the island.