From Longman Dictionary of Contemporary Englishseawallsea‧wall /ˌsiːˈwɔːl $ ˈsiːwɒːl/ noun [countable] TBa wall built beside the sea to stop the water from flowing onto the land
Examples from the Corpus
seawall• The fires combined into a raging firestorm, driving the survivors toward the seawall, where they were struck by the waves. 