Where does “kaitsõ” come from?

kaitsõ (Livonian) comes from Proto-Finnic kaiccedak — to watch over, to guard, to keep safe.

Ancestry of “kaitsõ”, step by step

Step	Language	Word	Meaning
1	Proto-Finnic	kaiccedak	to watch over, to guard, to keep safe

kaitsõ — Etymology, Origin & Word History | Etymology Explorer