disapproval vs subject matter

disapproval and subject matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
disapproval	Yes	No	No	No
subject matter	Yes	No	No	No

As nouns, subject matter is a hypernym of disapproval; that is, subject matter is a word with a broader meaning than disapproval:

Other hypernyms of disapproval include content, message, substance.

disapproval (noun)	subject matter (noun)
the act of disapproving or condemning	content communicating a message; what something is about
an inclination to withhold approval from some person or group
the expression of disapproval
a feeling of disliking something or what someone is doing