Where does “sihhur” come from?

sihhur (Old High German) comes from Proto-West Germanic sikur, from Latin sēcūrus, from Latin sē-, from Latin sex, from Proto-Italic seks, from Proto-Indo-European swéḱs — six.

Ancestry of “sihhur”, step by step

StepLanguageWordMeaning
1Proto-West Germanicsikursecure, safe; sure, certain
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 →