Where does “amplitudo” come from?

amplitudo (Latin) comes from Latin amplus, from Latin -ō, from Proto-Indo-European -ō — Derives nouns from roots.

Ancestry of “amplitudo”, step by step

Step	Language	Word	Meaning
1	Latin	amplus	large, spacious, roomy; abundant, ample;...
2	Latin	-ō	—
3	Proto-Indo-European	-ō	Derives nouns from roots

amplitudo — Etymology, Origin & Word History | Etymology Explorer