Where does “ultimatum” come from?

ultimatum (Dutch) comes from Latin ultimatum, from Latin ultimatus, from Latin ultimus, from Proto-Italic *oltm̥mos.

ultimatum (Dutch): ultimatum

Definitions

Step	Language	Word	Meaning
1	Latin	ultimatum	accusative supine of ultimō
2	Latin	ultimatus	done, finished
3	Latin	ultimus	last, final; furthest, farthest
4	Proto-Italic	*oltm̥mos	—

ultimatum — Etymology, Origin & Word History | Etymology Explorer