grass wrack vs sea wrack

grass wrack and sea wrack both are nouns.

Word	Noun	Adjective	Verb	Adverb
grass wrack	Yes	No	No	No
sea wrack	Yes	No	No	No

As nouns, grass wrack and sea wrack are synonyms defined as:

grass wrack and sea wrack: submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts

Other synonyms of grass wrack include eelgrass, Zostera marina.

grass wrack (noun)	sea wrack (noun)
submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts	growth of marine vegetation especially of the large forms such as rockweeds and kelp
	submerged marine plant with very long narrow leaves found in abundance along North Atlantic coasts