organism vs causal agent

organism and causal agent both are nouns.

Word	Noun	Adjective	Verb	Adverb
organism	Yes	No	No	No
causal agent	Yes	No	No	No

As nouns, causal agent is a hypernym of organism; that is, causal agent is a word with a broader meaning than organism:

organism: a living thing that has (or can develop) the ability to act or function independently
causal agent: any entity that produces an effect or is responsible for events or results

Other hypernyms of organism include animate thing, living thing, causal agency, cause.

organism (noun)	causal agent (noun)
a living thing that has (or can develop) the ability to act or function independently	any entity that produces an effect or is responsible for events or results
a system considered analogous in structure or function to a living body