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cosmic ray (plural cosmic rays)

1. (astronomy) Any of a range of subatomic particles, and thus also electromagnetic waves, that permeate the universe owing to their various origins within stars or from collisions outside stars. (Life on Earth is mostly shielded from them by the Earth's magnetic field, but a small amount strikes us all each day.)

   Hypernym: ray

   Holonym: radiation

   For some applications, software architecture needs to be capable of tolerating bitflips from cosmic rays, through methods such as parameter value refreshes and sanity checks.