This is the 12074th most frequent Polish word.
litr
"Litr" in Polish means "liter," a unit of volume measurement in the metric system.
The word 'litr' is used here as a noun to describe a unit of volume, specifically the amount of milk.
Mam litr mleka w lodówce.
I have a liter of milk in the fridge.
Here 'litr' forms part of a quantitative phrase describing the required volume for an activity, expressed in plural as 'litrów'.
Potrzebuję dwóch litrów wody do przepisu.
I need two liters of water for the recipe.
In this sentence, 'litr' is a unit of measurement to quantify the amount of fuel purchased.