sea roaches Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition plural noun. a type of marine crustacean often found in coastal waters. Example Sentence The sea roaches are gross. Spelled as two words. More Example Sentences Sea roaches help clean the ocean floor. Synonyms marine insects; isopods; aquatic roaches Antonyms bird Hear It! Say It! Write It! sea roaches Switch to cursive Start Share with your friends: