Learn how to say Gallon correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word gallon:
1a unit of volume for liquid measure equal to eight pints, in particular:
(also imperial gallon) British (also used for dry measure) a unit of volume equivalent to 4.55 litres.
US a unit of volume equivalent to 3.79 litres.
2 (gallons of) informal a large volume of something:
gallons of fake blood
Middle English: from Anglo-Norman French galon, from the base of medieval Latin galleta, galletum ‘pail, liquid measure’, perhaps of Celtic origin