请输入您要查询的英文单词:

 

单词 penumbra
释义

WordReference Random House Unabridged Dictionary of American English © 2024
pe•num•bra  (pi numbrə),USA pronunciation n., pl. -brae (-brē),USA pronunciation -bras. 
  1. Astronomy
    • the partial or imperfect shadow outside the complete shadow of an opaque body, as a planet, where the light from the source of illumination is only partly cut off. Cf. umbra (def. 3a).
    • the grayish marginal portion of a sunspot. Cf. umbra (def. 3b).
  2. a shadowy, indefinite, or marginal area.
  • Neo-Latin, equivalent. to Latin paen- pen- + umbra shade
  • 1660–70
pe•numbral, pe•numbrous, adj. 

Collins Concise English Dictionary © HarperCollins Publishers::
penumbra /pɪˈnʌmbrə/ n ( pl -brae / -briː/, -bras)
  1. a fringe region of half shadow resulting from the partial obstruction of light by an opaque object
  2. the lighter and outer region of a sunspot
  3. the point or area in which light and shade blend

Compare umbraEtymology: 17th Century: via New Latin from Latin paene almost + umbra shadow

peˈnumbral, peˈnumbrous adj
随便看

 

英语词典包含188688条英英释义在线翻译词条,基本涵盖了全部常用单词的英英翻译及用法,是英语学习的有利工具。

 

Copyright © 2004-2022 Newdu.com All Rights Reserved
更新时间:2025/2/23 9:15:10