Definition: XO

Abbreviation (acronym for "Extra Old") appearing on the labels of many spirits, particularly the oldest superior cognacs, indicating that the youngest brandy in the blend has been aged for at least six and a half years in barrels. This quality classification is also used for Armagnac and Calvados. In practice, the age of an XO, Napoléon, Extra or Hors-d'Âge is significantly higher. See cognac.