This is the 162nd most frequent Italian word.
ultimi
"Ultimi" means "last" or "final ones" in English.
Here, 'ultimi' is used to refer to the final days of the vacation, indicating the end of a period or event.
Gli ultimi giorni di vacanza sono stati i più belli.
The last days of vacation were the most beautiful.
In this sentence, 'ultimi' describes the final chapters of the book, again marking the concluding parts of something.
Ho letto gli ultimi capitoli del libro ieri sera.
I read the last chapters of the book last night.
Here, 'ultimi' refers to the most recent individuals to arrive, indicating temporality and chronological order.