Orion vs gaseous nebula

Orion and gaseous nebula both are nouns.

Word	Noun	Adjective	Verb	Adverb
Orion	Yes	No	No	No
gaseous nebula	Yes	No	No	No

As nouns, gaseous nebula is a hypernym of Orion; that is, gaseous nebula is a word with a broader meaning than Orion:

Orion: a constellation on the equator to the east of Taurus; contains Betelgeuse and Rigel
gaseous nebula: a cluster of stars within an intricate cloud of gas and dust

Other hypernyms of Orion include diffuse nebula.

Orion (noun)	gaseous nebula (noun)
a constellation on the equator to the east of Taurus; contains Betelgeuse and Rigel	a cluster of stars within an intricate cloud of gas and dust
(Greek mythology) a giant Boeotian hunter who pursued the Pleiades and was eventually slain by Artemis; was then placed in the sky as a constellation