This is the 5578th most frequent Russian word.
последним
"Последним" means "the last" in English.
Here 'последним' means 'the last one' in the sense of being the final element in a list or sequence.
Его выбор оказался последним в списке.
His choice turned out to be the last on the list.
In this sentence, 'последним' figuratively means a person with the least deserving qualities among a group.
Своим поступком он стал последним, кто заслуживает уважения.
By his act, he became the last one deserving respect.
The word 'последним' is used here to describe time: the final evening in a specified period.