Where does “sicurissimo” come from?

sicurissimo (Italian) comes from Italian sicuro, from Latin sēcūrus, from Latin sē-, from Latin sex, from Proto-Italic seks, from Proto-Indo-European swéḱs — six.

Ancestry of “sicurissimo”, step by step

StepLanguageWordMeaning
1Italiansicurosafe, secure; certain, sure; surely, for sure,...
2Latinsēcūruscareless, negligent
3Latinsē-apart-; aside-; away
4Latinsexsix; 6
5Proto-Italicsekssix
6Proto-Indo-Europeanswéḱssix
Every word from Proto-Indo-European swéḱs →Every word from Latin sē- →Every word from Proto-Italic seks →