penumbra [pi-nuhm-bruh] ExamplesWord Origin noun, plural pe·num·brae [pi-nuhm-bree] /pɪˈnʌm bri/, pe·num·bras.
- a shadowy, indefinite, or marginal area.
Origin of penumbra 1660–70; New Latin, equivalent to Latin paen- pen- + umbra shadeRelated formspe·num·bral, pe·num·brous, adjective Examples from the Web for penumbral Historical Examples of penumbral
The line between the real and imaginary is vague and penumbral to us.
It may be that all the elements of the penumbral cone intersect the earth.
Isabel snuck into the guest bedroom and settled into an overstuffed armchair at a penumbral corner.
Strange, penumbral, characters roam the boardrooms of banks in the countries in transition.
The penumbral line is marked from hour to hour on the maps given annually in the American Ephemeris.
British Dictionary definitions for penumbral penumbra noun plural -brae (-briː) or -bras
- a fringe region of half shadow resulting from the partial obstruction of light by an opaque object
- astronomy the lighter and outer region of a sunspot
- painting the point or area in which light and shade blend
Compare umbra Derived Formspenumbral or penumbrous, adjectiveWord Origin for penumbra C17: via New Latin from Latin paene almost + umbra shadow Word Origin and History for penumbral penumbra n.
1660s, from Modern Latin penumbra “partial shadow outside the complete shadow of an eclipse,” coined 1604 by Kepler from Latin pæne “almost” + umbra “shadow” (see umbrage). Related: Penumbral.
penumbral in Science penumbra [pĭ-nŭm′brə] Plural penumbras penumbrae (pĭ-nŭm′brē)
- A partial shadow between regions of full shadow (the umbra) and full illumination, especially as cast by Earth, the Moon, or another body during an eclipse. During a partial lunar eclipse, a portion of the Moon’s disk remains within the penumbra of Earth’s shadow while the rest is darkened by the umbra. See Note at eclipse.
- The grayish outer part of a sunspot. Compare umbra.