Dictionary Definitions from Oxford Languages · Learn more noun 1. PHYSICS the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionization. Radiation An energy force so great it can take out countries But so helpful it can help cure and find diseases in the human body But imagine the typical green substance that gives ordinary people super powers Now imagine that substance flowing through your veins and being able to control and release it at will Well that's what Y/n L/n can do Y/n was born with an abnormal quirk compared to the rest of her family A mutated emitter type quirk really Read and watch as her power blossoms as well as her relationship With a certain icy hot boy whose quirk just seems to compliment hers very well.