Where does “ultima” come from?

ultima (Portuguese) comes from Portuguese ultimar, from Latin ultimō, from Latin ultimus, from Proto-Italic *oltm̥mos.

ultima (Portuguese): third-person singular present indicative of...

Definitions

Step	Language	Word	Meaning
1	Portuguese	ultimar	to finalize, finish
2	Latin	ultimō	—
3	Latin	ultimus	last, final; furthest, farthest
4	Proto-Italic	*oltm̥mos	—

ultima — Etymology, Origin & Word History | Etymology Explorer