Where does “lustro” come from?

lustro (Latin) comes from Latin lūstrum, from Old Latin loustrom, from Proto-Indo-European lewkstrom, from Proto-Indo-European lewk- — bright; to shine; to see.

Ancestry of “lustro”, step by step

Step	Language	Word	Meaning
1	Latin	lūstrum	—
2	Old Latin	loustrom	—
3	Proto-Indo-European	lewkstrom	—
4	Proto-Indo-European	lewk-	bright; to shine; to see

Every word from Proto-Indo-European lewk- →

lustro — Etymology, Origin & Word History | Etymology Explorer