firkin

fir-, 四分之一，词源同fourth. -kin, 小词后缀。即四分之一桶，用来指一种小桶。

firkin (n.)

"small cask," late 14c., apparently from Middle Dutch *vierdekijn, diminutive of vierde, literally "fourth, fourth part" (see fourth); so called because it usually is the fourth part of a barrel.

1. a British unit of capacity equal to 9 imperial gallons

2. a small wooden keg