From racemus, a Latin word meaning a cluster of grapes, French derived the word raisin, meaning a single grape. English adopted this French word in the fourteenth century, first using it as a synonym for grape (which had been adopted a hundred years earlier) and then shifting its application to a special kind of grape, one dried in the sun until it resembles a wizened Winston Churchill. A single word, therefore, has shifted its meaning over the centuries from a cluster of grapes (the Latin racemus), to one grape (the French raisin), to one dried grape (the English raisin). It should be duly noted that raisin is in no way related to raison d’etre or raisin’hell.
Raisins, those delightful treats, are the result of transforming either green or black grapes into a dried state, achieved through the gentle desiccation process of sun-drying or aided by artificial means.