Also colloquially "calva". A drink made from distilled cider.
Widly - and illegally - produced and consumed locally in northwestern France, with strength of about 70%.
A truck or cart mounted still goes from farm to farm in rural areas, and local officials (le Mairie) are bribed with a portion of the produce.
The resulting drink is dark brown and highly volatile, and is often consumed mixed in coffee or as an apperitif.