transmission density vs density

transmission density and density both are nouns.

Word	Noun	Adjective	Verb	Adverb
transmission density	Yes	No	No	No
density	Yes	No	No	No

As nouns, density is a hypernym of transmission density; that is, density is a word with a broader meaning than transmission density:

transmission density: (physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation
density: the amount per unit size

Other hypernyms of transmission density include denseness.

transmission density (noun)	density (noun)
(physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation	the amount per unit size
	the spatial property of being crowded together