actinic

From Ancient Greek ἀκτίς, ἀκτῖν- (aktís, aktîn-, “ray”) +‎ -ic.

• IPA^(key): /ækˈtɪn ɪk/
• Rhymes: -ɪnɪk

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actinic (not comparable)

1. Related to radiation; used most often in reference to light, especially in the ultraviolet range.
2. (by extension) Harsh and bright.
   • 1999, Jody Lynn Nye, School of Light:

     He bounded over cresting waves that shone in the actinic glare.

3. (medicine) Caused by extensive exposure to ultraviolet light.

   In medicine, actinic keratoses usually occur in sundamaged skin and exhibit hyperkeratosis.^[1]

4. (chemistry, photography) Of or relating to actinism, the range of photochemical effects produced by exposure to EM radiation, particularly sunlight.
   • 1883, Abraham Cowley Malley, Micro-photography: Including a Description of the Wet Collodion and Gelatino-Bromide Processes, page 32:

     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.

   • 1943 May and June, Chas. S. Lake, “Some Continental Travel Experiences (1922-1939)—III”, in Railway Magazine, page 141:

     I got my picture, and it turned out quite a good one, despite the rather poor light which at that time of day, 7 p.m., was lacking in actinic value.

5. Composed of actin.

• “actinic”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.

• cantici

Borrowed from French actinique.

actinic m or n (feminine singular actinică, masculine plural actinici, feminine and neuter plural actinice)

1. actinic