"Raw," in our household term for certain wines, refers to the treatment of the essential ingredients in the first stages of wine-making.
While winemakers besides us must have a term at hand that carries the same meaning, we lack knowledge of any such ... so we keep speaking of "raw wines." (I half suspect some passing note in H.E. Bravery or Terry Garey suggested or gave us the term, though.)
The basic ingredients in a raw wine are used in a raw state; in a cooked wine, in a cooked state. The spring wines offer a nice illustration of the difference.
Dandelion wine, as we have made it thus far, is a cooked wine: the water is boiled and then poured, while still boiling-hot, over the flowers. (This stage of dandelion winemaking we do in enamelware, not in a crock; the water-and-flower mixture then cools, while covered.)
Rhubarb wine, on the other hand, is a raw wine: the water is boiled, as a sterilizing measure, then allowed to cool in a covered enamelware pot. Only after cooling is it poured over rhubarb pieces.
As it happens, we have never attempted a cooked rhubarb wine. One early recipe we found -- early in our winemaking, and early in its publication date ... as I recall, around the earlier 1900s -- was a rhubarb wine recipe. Simple though it was, it seems to have pointed us in the right direction for quality home winemaking.