breakwater vs groyne

breakwater and groyne both are nouns.

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

As nouns, breakwater and groyne are synonyms defined as:

breakwater 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 breakwater include bulwark, groin, jetty, mole, seawall.

breakwater (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