lung vs respiratory organ

lung and respiratory organ both are nouns.

Word	Noun	Adjective	Verb	Adverb
lung	Yes	No	No	No
respiratory organ	Yes	No	No	No

As nouns, respiratory organ is a hypernym of lung; that is, respiratory organ is a word with a broader meaning than lung:

lung: either of two saclike respiratory organs in the chest of vertebrates; serves to remove carbon dioxide and provide oxygen to the blood
respiratory organ: any organ involved in the process of respiration

lung (noun)	respiratory organ (noun)
either of two saclike respiratory organs in the chest of vertebrates; serves to remove carbon dioxide and provide oxygen to the blood	any organ involved in the process of respiration