green turtle soup vs turtle soup

green turtle soup and turtle soup both are nouns.

Word	Noun	Adjective	Verb	Adverb
green turtle soup	Yes	No	No	No
turtle soup	Yes	No	No	No

As nouns, green turtle soup and turtle soup are synonyms defined as:

green turtle soup and turtle soup: soup usually made of the flesh of green turtles

green turtle soup (noun)	turtle soup (noun)
soup usually made of the flesh of green turtles	soup usually made of the flesh of green turtles