Where does “nostalgia” come from?

nostalgia (Late Latin) comes from Ancient Greek νόστος, from Ancient Greek -τος, from Proto-Indo-European -tós — Creates verbal adjectives from verb stems.

Ancestry of “nostalgia”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	νόστος	the act of reaching a place: journey, arrival;...
2	Ancient Greek	-τος	Creates perfective passive verbal adjectives;...
3	Proto-Indo-European	-tós	Creates verbal adjectives from verb stems

Every word from Proto-Indo-European -tós →Every word from Ancient Greek -τος →Every word from Ancient Greek νόστος →