Definition - What does Brilliant mean?
In the context of wine making styles, brilliant refers to a wine that is very clear and contains no sediment. The brilliance of a wine, is a direct result of the wine style and the way the wine was made, filtered and bottled, and is not a characteristic of the varietal. Brilliance should not be confused with the characteristic of color, however, brilliance will affect the perception of the color of the wine and brilliance or the lack of brilliance can affect the weight or mouthfeel of a wine.
WineFrog explains Brilliant
Brilliance in wine can be observed regardless of the color or opacity of the wine, as brilliance simply means that the wine is clear and free from sediment. Wines that are exceptionally brilliant have most likely been filtered many times to achieve clarity and to remove cloudiness. How brilliant a wine is, depends on the wine style and the winemaking process. Some wines are notoriously brilliant, like very dry sparkling wines, while other wines are intentionally un-brilliant, as is the case with unfiltered wines. Wines that are unfiltered will be cloudy with sediment and may have a lightly grainy mouthfeel.