Why are raisins called raisins?

Raisins are called so because they are dried grapes. The word 'raisin' comes from the Old French word 'raisin', which in turn comes from the Latin word 'racemus', meaning 'bunch of grapes'. When grapes are dried, they shrivel up and become concentrated in flavour, creating the delicious and nutritious fruit we know as raisins.