Where does “sestaio” come from?

sestaio (Italian) comes from Latin sextarius, from Latin Sextus, from Latin sex, from Proto-Italic seks, from Proto-Indo-European swéḱs — six.

Ancestry of “sestaio”, step by step

StepLanguageWordMeaning
1Latinsextariussextarius, the sixth part
2LatinSextusparticularly popular in Gaul. (Occasionally also found as a cognomen.) In particular
3Latinsexsix; 6
4Proto-Italicsekssix
5Proto-Indo-Europeanswéḱssix
Every word from Proto-Indo-European swéḱs →Every word from Proto-Italic seks →Every word from Latin sex →
sestaio — Etymology, Origin & Word History | Etymology Explorer