lateral line vs lateral line organ

lateral line and lateral line organ both are nouns.

Word	Noun	Adjective	Verb	Adverb
lateral line	Yes	No	No	No
lateral line organ	Yes	No	No	No

As nouns, lateral line and lateral line organ are synonyms defined as:

lateral line and lateral line organ: sense organs of fish and amphibians; believed to detect pressure changes in the water

lateral line (noun)	lateral line organ (noun)
sense organs of fish and amphibians; believed to detect pressure changes in the water	sense organs of fish and amphibians; believed to detect pressure changes in the water