eclipse

Short definition from Wiktionary

Noun

1. 1
   An alignment of astronomical objects whereby one object comes between the observer (or notional observer) and another object, thus obscuring the latter.
2. 2
   Especially, an alignment whereby a planetary object (for example, the Moon) comes between the Sun and another planetary object (for example, the Earth), resulting in a shadow being cast by the middle planetary object onto the other planetary object.
3. 3
   A seasonal state of plumage in some birds, notably ducks, adopted temporarily after the breeding season and characterised by a dull and scruffy appearance.
4. 4
   Obscurity, decline, downfall.

Verb

1. 1
   Of astronomical or atmospheric bodies, to cause an eclipse.
2. 2
   To overshadow; to be better or more noticeable than.
3. 3
   To undergo eclipsis.