noun. The act of obscuring or darkening; the state of being darkened or obscured; the act or state of being made obscure or indistinct: as, the obscuration of the moon in an eclipse.

noun. The act or operation of obscuring; the state of being obscured.

noun. the state of being obscured

"Solar eclipse, whereas in the case of a lunar eclipse the obscuration is the same in degree at all parts of the Earth where the Moon is visible."

darkening  hiding  

aberration  adumbration  discompose  discomposure  enfeeblement