Where does “ambassador” come from?

Ambassador comes from Middle English ambassadore, from Anglo-Norman ambassadeur, from Italian ambassadore.

ambassador (English): A minister of the highest rank sent to a foreign...

Definitions

Step	Language	Word	Meaning
1	Middle English	ambassadore	—
2	Anglo-Norman	ambassadeur	ambassador
3	Old Italian	ambassadore	—
4	Old Occitan	ambaisador	ambassador
5	Old Occitan	ambaissa	service, mission, errand; message
6	Latin	ambactia	—
7	Proto-Germanic	ambahtiją	service, ministry, office, message
8	Proto-Germanic	ambahtaz	servant
9	Gaulish	ambaxtos	vassal, high-ranking servant
10	Proto-Celtic	ambaxtos	servant
11	Proto-Indo-European	h₂eǵ-	to drive

ambassador — Etymology, Origin & Word History | Etymology Explorer