Where does “causal” come from?

causal (Portuguese) comes from Late Latin causalis, from Latin causa, from Old Latin caussa, from Proto-Indo-European kawd-teh₂.

causal (Portuguese): causal of, relating to or being a cause of something

Definitions

Step	Language	Word	Meaning
1	Late Latin	causalis	causal
2	Latin	causa	cause, reason; case, claim, contention; motive,...
3	Old Latin	caussa	cause, reason, purpose; case, claim; Archaic form...
4	Proto-Indo-European	kawd-teh₂	—