Cognac

wiktionary

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French cognac, from Cognac, a city in France, from Medieval Latin Comniacum, from the name Cominius + Gallo-Roman suffix -acum.

etymonline

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cognac (n.)

1590s, Conniacke wine, "wine produced in Cognac," the region in western France. The sense of "brandy of a superior quality distilled from wines produced in the Cognac region" is from 1680s as Cognac brandy; by 1755 simply as Cognac. Also sometimes used generally of any brandy of good quality. The place name is from Medieval Latin Comniacum, from the personal name Cominius and the Gallo-Roman suffix -acum.