Meaning of Jax. English name. In English, the name Jax means-God has been gracious; has shown favor. Based on John or Jacques.. Other origins for the name Jax include-English, American, Spanish.The name Jax is most often used as a boy name or male name. English Name Meaning-God has been gracious; has shown favor.Based on John or Jacques.ther origins for the name Jax include-English, American, Spanish.The name Jax is most often used as a boy name or male name. English Name Meaning-God has been gracious; has shown favor. Based on John or Jacques.