rock lobster vs sea crawfish

rock lobster and sea crawfish both are nouns.

Word	Noun	Adjective	Verb	Adverb
rock lobster	Yes	No	No	No
sea crawfish	Yes	No	No	No

As nouns, rock lobster and sea crawfish are synonyms defined as:

rock lobster and sea crawfish: large edible marine crustacean having a spiny carapace but lacking the large pincers of true lobsters

Other synonyms of rock lobster include crawfish, crayfish, langouste, spiny lobster.

rock lobster (noun)	sea crawfish (noun)
large edible marine crustacean having a spiny carapace but lacking the large pincers of true lobsters	large edible marine crustacean having a spiny carapace but lacking the large pincers of true lobsters
warm-water lobsters without claws; those from Australia and South Africa usually marketed as frozen tails; caught also in Florida and California