Original: While raisin is a French loanword, the word in French refers to the fresh fruit; grappe (from which the English grape is derived) refers to the bunch (as in une grappe de raisins).
Simplified: Note that, while raisin is a French loanword, the word in French means the fresh fruit. Grappe (Where the English word grape comes from) means the bunch (as in une grappe de raisin).