Толковый словарь английского языка - penumbra

noun (plural ~e or -bras) see: umbrage Date: 1666 1. a space of partial illumination (as in an eclipse) between the perfect shadow on all sides and the full light, a shaded region surrounding the dark central portion of a sunspot, a surrounding or adjoining region in which something exists in a lesser degree ; fringe, a body of rights held to be guaranteed by implication in a civil constitution, something that covers, surrounds, or obscures ; shroud , ~l adjective