sunspot(redirected from Penumbra (Sun))
Also found in: Dictionary, Thesaurus, Encyclopedia.
(1) Actinic keratosis, see there.
(2) Actinic lentigo, see there.
A region of intense magnetic activity on the sun’s surface resulting in a local reduction in convection and temperature, which appears are dark spots.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.