actinic /ækˈtɪn ɪk/ adjective5 •Related to radiation; used most often in reference to light, especially in the ultraviolet range. •Caused by extensive exposure to ultraviolet light.In medicine, actinic keratoses usually occur in sundamaged skin and exhibit hyperkeratosis. •Of or relating to actinism, the range of photochemical effects produced by exposure to electromagnetic radiation, particularly sunlight.It should be borne in mind that the actinic power of the sun is subject to considerable variations, due to its elevation above the horizon. — 1883 •Harsh and bright, especially blindingly so.He bounded over cresting waves that shone in the actinic glare. — 1999 •Composed of actin.
