passing comment vs obiter dictum

passing comment and obiter dictum both are nouns.

Word	Noun	Adjective	Verb	Adverb
passing comment	Yes	No	No	No
obiter dictum	Yes	No	No	No

As nouns, passing comment and obiter dictum are synonyms defined as:

passing comment (noun)	obiter dictum (noun)
an incidental remark	an opinion voiced by a judge on a point of law not directly bearing on the case in question and therefore not binding
	an incidental remark