释义 |
WordReference Random House Unabridged Dictionary of American English © 2024pe•num•bra (pi num′brə),USA pronunciation n., pl. -brae (-brē),USA pronunciation -bras. - 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).
- a shadowy, indefinite, or marginal area.
- Neo-Latin, equivalent. to Latin paen- pen- + umbra shade
- 1660–70
pe•num′bral, pe•num′brous, adj. |