Where does “*exquarto” come from?

*exquarto (Vulgar Latin) comes from Latin quārtus, from Proto-Indo-European kʷeturtos, from Proto-Indo-European kʷetwóres, from Proto-Indo-European kʷe- — and.

Ancestry of “*exquarto”, step by step

Step	Language	Word	Meaning
1	Latin	quārtus	—
2	Proto-Indo-European	kʷeturtos	—
3	Proto-Indo-European	kʷetwóres	four
4	Proto-Indo-European	kʷe-	and

Every word from Proto-Indo-European kʷe- →

*exquarto — Etymology, Origin & Word History | Etymology Explorer