Where does “undecimus” come from?

undecimus (Latin) comes from Latin undecim, from Latin oinodecem, from Proto-Indo-European óynom déḱm̥t.

undecimus (Latin): eleventh

Definitions

Step	Language	Word	Meaning
1	Latin	undecim	eleven; 11
2	Latin	oinodecem	—
3	Proto-Indo-European	óynom déḱm̥t	—

undecimus — Etymology, Origin & Word History | Etymology Explorer