kilderkin

noun

1. a unit of capacity, usually equal to half a barrel or two firkins.
2. an English unit of capacity, equal to 18 imperial gallons (82 liters).

noun

1. an obsolete unit of liquid capacity equal to 16 or 18 Imperial gallons or of dry capacity equal to 16 or 18 wine gallons
2. a cask capable of holding a kilderkin