Penumbra



GRE Barron

解释

GRE 红宝书

• n. 半明半暗之处; 边缘部分
• ［英］ n. 半明半暗之处 ( a space of partial illumination) ; 边缘部分 ( fringe)
• ［记］ pen ( 接近) ＋umbra ( 影子) -> 接近影子 -> 明暗交界处
• ［同］ 同根词: adumbrate ( 预示) ; umbrella ( 雨伞)

Webster Collegiate

noun (plural penumbrae or -bras)

• Etymology: New Latin, from Latin paene almost + umbra shadow — more at umbrage
• Date: 1666
• 1.
  • a. a space of partial illumination (as in an eclipse) between the perfect shadow on all sides and the full light
  • b. a shaded region surrounding the dark central portion of a sunspot
• 2. a surrounding or adjoining region in which something exists in a lesser degree ; fringe
• 3. a body of rights held to be guaranteed by implication in a civil constitution
• 4. something that covers, surrounds, or obscures ; shroud <a penumbra of secrecy><a penumbra of somber dignity has descended over his reputation — James Atlas>
• ? penumbral adjective

---