·noun A small wooden vessel or cask of indeterminate size, — used for butter, lard, ·etc.
II. Firkin ·noun A varying measure of capacity, usually being the fourth part of a barrel; specifically, a measure equal to nine imperial gallons.
Used only in John 2:6; the Attic amphora, equivalent to the Hebrew bath (q.v.), a measure for liquid...
Easton's Bible Dictionary
[Weights And Measures AND Measures] ...
William Smith's Bible Dictionary