occultation

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act of occulting or the state of being occulted.
2. n. Astronomy The passage of a celestial body across a line between an observer and another celestial object, as when the moon moves between Earth and the sun in a solar eclipse.
3. n. Astronomy The progressive blocking of light, radio waves, or other radiation from a celestial source during such a passage.
4. n. Astronomy An observational technique for determining the position or radiant structure of a celestial source so occulted: a lunar occultation of a quasar.

Century Dictionary and Cyclopedia

1. n. The act of hiding or concealing, or the state of being hidden or concealed; especially, the hiding of one body from sight by another; specifically, in astronomy, the hiding of a star or planet from sight by its passing behind some other of the heavenly bodies. It is particularly applied to the eclipse of a fixed star by the moon.
2. n. Figuratively, disappearance from view; withdrawal from notice.

Wiktionary

1. n. astronomy An astronomical event that occurs when one celestial object is hidden by another celestial object that passes between it and the observer when the nearer object appears larger and completely hides the more distant object
2. n. , Describes the state of an imam that has been hidden by Allah.

GNU Webster's 1913

1. n. (Astron.) The hiding of a heavenly body from sight by the intervention of some other of the heavenly bodies; -- applied especially to eclipses of stars and planets by the moon, and to the eclipses of satellites of planets by their primaries.
2. n. The state of being occult.

WordNet 3.0

1. n. one celestial body obscures another