Where does “cateno” come from?

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

Ancestry of “cateno”, step by step

Step	Language	Word	Meaning
1	Latin	-ō	—
2	Proto-Indo-European	-ō	Derives nouns from roots

cateno — Etymology, Origin & Word History | Etymology Explorer