This is the 3143rd most frequent Russian word.
лист
The Russian word "лист" can mean "leaf" (of a plant) or "sheet" (of paper).
In this sentence, 'лист' refers to a single sheet or piece of paper.
На столе лежит лист бумаги.
A sheet of paper is lying on the table.
Here, 'лист' in the plural form 'листья' refers to the leaves of a tree.
Осенью деревья теряют свои листья.
In autumn, trees lose their leaves.
The term 'лист' here denotes one page of a calendar.