This is the 368th most frequent Polish word.
ostatni
"Last" or "final."
Here, "ostatni" is an adjective, indicating the final item in a chronological sequence.
To jest mój ostatni dzień w pracy.
This is my last day at work.
In this case, "ostatni" is used as an adjective to describe a singular remaining object in a group.
Został nam ostatni kawałek pizzy.
We have the last slice of pizza left.
"Ostatni" is an adjective identifying the final person in line or order.