Where does “περυσινός” come from?

περυσινός (Ancient Greek) comes from Ancient Greek πέρυσι, from Proto-Indo-European péruti, from Proto-Indo-European per — around; through.

Ancestry of “περυσινός”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	πέρυσι	a year ago, last year
2	Proto-Indo-European	péruti	last year
3	Proto-Indo-European	per	around; through