Alternative letter-case form of X-ray

Alternative spelling of γ-ray

(engineering) Electromagnetic waves with frequencies intermediate between, and sharing properties of both, short radio waves and long IR optical waves. This region is defined variously as between 0.1 - 10 THz, 0.3-3 THz or 0.3-30 THz.

Alternative spelling of ray gun

Alternative spelling of death ray

A sunbeam seen just after sunset or just before sunrise, caused by a cloud below the horizon and dust particles in the air above the horizon. / A cloud shadow cast on the bright sky.

(astronomy) An energetic particle originating outside our solar system. / (astronomy) Cosmic radiation: a stream of cosmic rays.

Very high frequency (and therefore very high energy) electromagnetic radiation emitted as a consequence of radioactivity.

(optics) A ray that passes through the axis of the optical fiber.

Any of several very large pelagic rays formerly of the genus Manta, now placed in genus Mobula, with winglike pectoral fins, a long tail, and two fins resembling horns that project from the head.