Where does “sacramentum” come from?

sacramentum (Latin) comes from Latin sacrō, from Latin sacer, from Proto-Indo-European sh₂krós, from Proto-Indo-European seh₂k- — sacred.

Ancestry of “sacramentum”, step by step

Step	Language	Word	Meaning
1	Latin	sacrō	—
2	Latin	sacer	sacred, holy, dedicated , consecrated, hallowed;...
3	Proto-Indo-European	sh₂krós	sacred
4	Proto-Indo-European	seh₂k-	sacred

sacramentum — Etymology, Origin & Word History | Etymology Explorer