Ma'anar ƙamus na "Radiation actinic" yana nufin radiation electromagnetic, musamman a cikin ultraviolet da blue na bakan, wanda ke da isasshen makamashi don haifar da halayen sinadarai ko lalata kyallen jikin halitta. Yawanci yana da alaƙa da tasirin hasken rana, da kuma sauran hanyoyin samun hasken rana kamar hasken X-ray da gamma. Kalmar "actinic" ta fito daga kalmar Helenanci "aktis," ma'ana "ray" ko "beam."