seawall vs groyne

seawall and groyne both are nouns.

Word	Noun	Adjective	Verb	Adverb
seawall	Yes	No	No	No
groyne	Yes	No	No	No

As nouns, seawall and groyne are synonyms defined as:

seawall and groyne: a protective structure of stone or concrete; extends from shore into the water to prevent a beach from washing away

Other synonyms of seawall include breakwater, bulwark, groin, jetty, mole.

seawall (noun)	groyne (noun)
a protective structure of stone or concrete; extends from shore into the water to prevent a beach from washing away	a protective structure of stone or concrete; extends from shore into the water to prevent a beach from washing away