asteroid belt Get Printable Handwriting Hear It! Say It! Write It! Learn It! Spelling Test Definition noun. a region in space between the orbits of Mars and Jupiter where most asteroids are found. Example Sentence The spaceship navigated carefully through the asteroid belt. Synonyms asteroid field; asteroid zone; minor-planet belt Antonyms planet; star Hear It! Say It! Write It! asteroid belt Switch to cursive Start Share with your friends: