Firkin (?), n. [From AS. feówer four (or an allied word, perh. Dutch or Danish) + -kin. See Four.] 1. A varying measure of capacity, usually being the fourth part of a barrel; specifically, a measure equal to nine imperial gallons. [Eng.]
[1913 Webster]

2. A small wooden vessel or cask of indeterminate size, -- used for butter, lard, etc. [U.S.]
[1913 Webster]