n.
Pronunciation: ˌ ä-( ˌ )k ə l- ' t ā -sh ə n
Function: noun
Date: 15th century
1 : the state of being hidden from view or lost to notice
2 : the interruption of the light from a celestial body or of the signals from a spacecraft by the intervention of a celestial body especially : an eclipse of a star or planet by the moon