opacity vs physical phenomenon

opacity and physical phenomenon both are nouns.

Word	Noun	Adjective	Verb	Adverb
opacity	Yes	No	No	No
physical phenomenon	Yes	No	No	No

As nouns, physical phenomenon is a hypernym of opacity; that is, physical phenomenon is a word with a broader meaning than opacity:

opacity: the phenomenon of not permitting the passage of electromagnetic radiation
physical phenomenon: a natural phenomenon involving the physical properties of matter and energy

opacity (noun)	physical phenomenon (noun)
the quality of being opaque to a degree; the degree to which something reduces the passage of light	a natural phenomenon involving the physical properties of matter and energy
incomprehensibility resulting from obscurity of meaning
the phenomenon of not permitting the passage of electromagnetic radiation