Definition - What does Saba mean?
In the context of winemaking, saba is a syrup, made from the must of crushed wine grapes. To make saba, the unfermented must is strained and then is slowly heated and reduced to make a thick, sweet syrup. Saba has been made for centuries and was once used as sweetener, though is now popular for many different culinary purposes and used to season meats, salads & vegetables.
WineFrog explains Saba
Saba, a fruity, mild syrup, is not alcoholic, as saba is made from unfermented must that is slowly heated for a long time to make a thick syrup. Saba is a thick, syrupy reduction, with concentrated sugars and flavors. Saba is used in recipes with all kinds of foods, or as a sauce along side dishes. Historically, saba was once used as sweetener in the place of honey. Saba is also known as mosto cotto, which is Italian for "cooked grape juice".