last
The Italian word 'ultimo' is commonly used to indicate something that comes at the end or after all others. It's similar to the English word 'last'. It can be used in different contexts, for example, in time ('l'ultimo giorno' means 'the last day'), in sequence ('l'ultimo della lista' means 'the last on the list'), or in order ('l'ultimo arrivato' means 'the last one to arrive').
The last train will leave at nine.
This sentence is using 'ultimo' to refer to the final train of a series of trains, leaving at a specific time.
This is my last day in Rome.
Here, 'ultimo' is used to indicate the final occurrence of something, in this instance, the speaker's final day in Rome.
I have read this author's latest book.
In this context, 'ultimo' refers to the most recent event, signalling the latest book released by this author.