firkin

lekkeri, nassakka

nelikko puhekieltä A varying measure of capacity, usually being the fourth part of a barrel; specifically, a measure equal to nine imperial gallons. Eng.
1882, James Edwin Thorold Rogers, A History of Agriculture and Prices in England, Volume 4, p. 205:

23 Hen. VIII, cap. 4... The barrel of beer is to hold 36 gallons, the kilderkin 18 gallons the firkin 9. But the barrel, kilderkin, and firkin of ale are to contain 32, 16, and 8 gallons.