E region vs Kennelly-Heaviside layer

E region and Kennelly-Heaviside layer both are nouns.

Word	Noun	Adjective	Verb	Adverb
E region	Yes	No	No	No
Kennelly-Heaviside layer	Yes	No	No	No

As nouns, E region and Kennelly-Heaviside layer are synonyms defined as:

E region and Kennelly-Heaviside layer: a region of the ionosphere (from 50 to 90 miles up) that reflects radio waves of medium length

Other synonyms of E region include E layer, Heaviside layer.

E region (noun)	Kennelly-Heaviside layer (noun)
a region of the ionosphere (from 50 to 90 miles up) that reflects radio waves of medium length	a region of the ionosphere (from 50 to 90 miles up) that reflects radio waves of medium length