Learn how to say Firkin correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word firkin:
a small cask formerly used for liquids, butter, or fish.
a unit of liquid volume equal to half a kilderkin (usually 9 imperial gallons or about 41 litres).
Middle English ferdekyn, probably from the Middle Dutch diminutive of vierde ‘fourth’ (a firkin originally contained a quarter of a barrel)