Source : Webster's Revised Unabridged Dictionary (1913)

Obscuration \Ob`scu*ra"tion\, n. [L. obscurativ: cf.F.
   obscuration. See {Obscure}, v. t. ]
   The act or operation of obscuring; the state of being
   obscured; as, the obscuration of the moon in an eclipse.
   --Sir J. Herschel.