Where does “сигуран” come from?

сигуран (Serbo-Croatian) comes from Venetian sigur, from Latin sēcūrus, from Latin sē-, from Latin sex, from Proto-Italic seks, from Proto-Indo-European swéḱs — six.

сигуран (Serbo-Croatian): sure; safe; reliable

Definitions

sure; safe; reliable

Ancestry of “сигуран”, step by step

Step	Language	Word	Meaning
1	Venetian	sigur	—
2	Latin	sēcūrus	careless, negligent
3	Latin	sē-	apart-; aside-; away
4	Latin	sex	six; 6
5	Proto-Italic	seks	six
6	Proto-Indo-European	swéḱs	six

Every word from Proto-Indo-European swéḱs →Every word from Latin sē- →Every word from Proto-Italic seks →