Webster's Revised Unabridged Dictionary · 1913

Causal

Causal , adjective

[Latin causalis. See Cause.]

Relating to a cause or causes; implying or containing a cause or causes; expressing a cause; causative.
Causal propositions are where two propositions are joined by causal words. — Watts

Causal , noun

A causal word or form of speech.
Anglo-Saxon drencan to drench, causal of Anglo-Saxon drincan to drink. — Skeat