topic vs res adjudicata

topic and res adjudicata both are nouns.

Word	Noun	Adjective	Verb	Adverb
topic	Yes	No	No	No
res adjudicata	Yes	No	No	No

As nouns, res adjudicata is a hyponym of topic; that is, res adjudicata is a word with a more specific, narrower meaning than topic:

Other hyponyms of topic include area, blind spot, remit, res judicata.

topic (noun)	res adjudicata (noun)
some situation or event that is thought about	a matter already settled in court; cannot be raised again
the subject matter of a conversation or discussion