English Dictionary: penumbra | by the DICT Development Group |
2 results for penumbra | |
From WordNet (r) 3.0 (2006) [wn]: | |
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From Webster's Revised Unabridged Dictionary (1913) [web1913]: | |
Penumbra \Pe*num"bra\, n. [NL., fr. L. paene almost + umbra shade.] 1. An incomplete or partial shadow. 2. (Astron.) The shadow cast, in an eclipse, where the light is partly, but not wholly, cut off by the intervening body; the space of partial illumination between the umbra, or perfect shadow, on all sides, and the full light. --Sir I. Newton. Note: The faint shade surrounding the dark central portion of a solar spot is also called the {penumbra}, and sometimes {umbra}. 3. (Paint.) The part of a picture where the shade imperceptibly blends with the light. |