Real Dictionary

noble rot in American English
noun: the fungus Botrytis cinerea, which is cultivated in some winemaking processes, esp. in the making of French Sauternes, where the ripened grapes become shriveled as a result of its introduction, thereby concentrating the juice and increasing the sugar cont

noble rot in British English
noun: a condition in which grapes are deliberately affected by Botrytis cinerea, resulting in the shrivelling of the ripened grapes, which in turn leads to an increased sugar content