The term TYPE OF RAY can refer to four different types of rays: Gamma Rays (5 letters), MANTA Rays (5 letters), COSMIC Rays (6 letters), and Cathode Rays (7 letters). Gamma Rays are a form of electromagnetic radiation, typically emitted from the nucleus of an atom. MANTA Rays are a species of ray-finned fish that inhabit tropical and subtropical oceans. COSMIC Rays are high-energy particles that originate from outside the Solar System. Finally, Cathode Rays are streams of electrons that are produced in a vacuum tube.