Definition - What does Light mean?
Light is a descriptive adjective that describes the mouthfeel or weight of a wine on the palate when tasting it. The body or weight of a wine is not subjective to the taster, but is directly related to the amount of alcohol in a wine, wines with a lower alcohol content are considered light.
WineFrog explains Light
Wines that are described as light have an alcohol content under 12.5%. When buying a wine, you don’t have to guess about the body of the wine, as wine labels are clearly marked with the alcohol content. The alcohol in wine is what gives the wine its viscosity, or body and determines the way the wine feels in our mouth and on the palate. Light bodied wines are often described as refreshing or crisp and are mostly associated with white wines such as Pinot Grigio, Sauvignon Blanc and Rose wines as well as red wines, like some French Burgundies.