Word of the day

Penumbra–  a surrounding area or fringe, a zone of influence or activity that is less distinct or certain; a partly shaded region between fully dark and fully lit; a part of a shadow in which only some of the light is blocked, used especially about a shadow made during an eclipse; partial shadow between regions of full shadow (the umbra) and full illumination; the diffuse area around the dark central area of a sunspot; something that covers, surrounds, or obscures; a shroud.