| 释义 |
WordReference Random House Unabridged Dictionary of American English © 2024um•bra (um′brə),USA pronunciation n., pl. -bras, -brae (-brē).USA pronunciation - shade;
shadow. - the invariable or characteristic accompaniment or companion of a person or thing.
- [Astron.]
- the complete or perfect shadow of an opaque body, as a planet, where the direct light from the source of illumination is completely cut off. Cf. penumbra (def. 1a).
- the dark central portion of a sunspot. Cf. penumbra (def. 1b).
- a phantom or shadowy apparition, as of someone or something not physically present;
ghost;
spectral image.
- Latin: shade, shadow
- 1590–1600
Collins Concise English Dictionary © HarperCollins Publishers:: umbra /ˈʌmbrə/ n ( pl -brae / -briː/, -bras)- a region of complete shadow resulting from the total obstruction of light by an opaque object, esp the shadow cast by the moon onto the earth during a solar eclipse
- the darker inner region of a sunspot
Compare penumbraEtymology: 16th Century: from Latin: shade, shadowˈumbral adj |