a fringe region of half shadow resulting from the partial obstruction of light by an opaque object
2. astronomy
the lighter and outer region of a sunspot
3. painting
the point or area in which light and shade blend
Compare umbra
Derived forms
penumbral (peˈnumbral) or penumbrous (peˈnumbrous)
adjective
Word origin
C17: via New Latin from Latin paene almost + umbra shadow
Examples of 'penumbrae' in a sentence
penumbrae
A falling gradient of febrile malaria incidence was identified in the penumbrae of both hotspots.
Philip Bejon, Thomas N Williams, Anne Liljander, Abdisalan M Noor, Juliana Wambua,Edna Ogada, Ally Olotu, Faith H A Osier, Simon I Hay, Anna Färnert, Kevin Marsh 2010, 'Stable and unstable malaria hotspots in longitudinal cohort studies in Kenya.', PLoS Medicinehttp://europepmc.org/articles/PMC2897769?pdf=render. Retrieved from PLOS CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)