eclipse

Concise Oxford English Dictionary © 2008 Oxford University Press:
eclipse /ɪˈklɪps/

▶noun

• 1 an obscuring of the light from one celestial body by the passage of another between it and the observer or between it and its source of illumination.

  ■ an instance of being eclipsed by another person or thing.

• 2 Ornithology a phase during which the distinctive markings of a bird (especially a male duck) are obscured by moulting of the breeding plumage.

▶verb

• 1 (of a celestial body) obscure the light from or to (another body).

• 2 deprive of significance, power, or prominence.

– origin ME: from OFr. e(s)clipse (n.), eclipser (v.), via L. from Gk ekleipsis, from ekleipein ‘fail to appear, be eclipsed’.