magnetic field lines Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. imaginary lines that show the direction of a magnetic field. Example Sentence Magnetic field lines spread out from one pole to the other. More Example Sentences They help us understand how magnets work. Synonyms magnetic lines; flux lines Antonyms linear; straight Hear It! Say It! Write It! magnetic field lines Switch to cursive Start Share with your friends: