Definition - What does Semi-Sweet mean?
In the context of wine tasting terms, semi-sweet is used to describe the amount of sweetness in a wine. Wines described as semi-sweet are typically very balanced and have smooth, well-rounded flavor profiles. Sweetness in a wine can be measured by the amount of residual sugar in the wine, however, when people taste wines, a semi-sweet wine would present sweetness in balance with other characteristics of the wine, including tannins, acidity and alcohol level.
WineFrog explains Semi-Sweet
Taste is always subjective to the person tasting and how developed their palate is, but specific characteristics of a wine can be described and agreed upon, and semi-sweetness is one of those characteristics. Sweetness, in general, is a measure of the amount of residual sugar in wine, however, it has to be in balance to be present on the palate. When a wine is semi-sweet, the residual sugar has to be in balance with the acidity and tannins, as these characteristics will counteract a wine's sweetness; for instance, wines with high sugar and high acidity will taste dry. Likewise the balance of sugar and alcohol enhance the perceived flavors of sweetness. Semi-sweet wines will have a well-rounded palate and while you will notice elements of the acidity, alcohol level and tannins in semi-sweet wines, none of those characteristics will be overpowering on the palate.