Actinic keratosis
WordNet
noun
(1) An overgrowth of skin layers resulting from extended exposure to the sun
WiktionaryText
Noun
- A lesion on the skin, typically on the upper portion of the head, characterized by discolored, thickened or scaly growths of keratin, caused by exposure to the sun; common in fair-complected people of a certain age. They are precancerous.