hammerheads Get Printable Handwriting Watch Say It Video Hear It! Say It! Write It! Learn It! Spelling Test Definition plural noun. a type of shark with a flat head shaped like a hammer. Example Sentence The hammerheads swim in the ocean. More Example Sentences These sharks have a unique head shape. Synonyms shark; predator; fish Antonyms dolphins; whales Hear It! Say It! Write It! hammerheads Switch to cursive Start Share with your friends: Watch Say It Video