Obtenebration
Pronunciation : Ob*ten`e*bra"tion
Part of Speech : n.
Etymology : [L. obtenebrate to make dark.]
Definition : Defn: The act of darkening; the state of being darkened; darkness. [Obs.] In every megrim or vertigo, there is an obtenebration joined with a semblance of turning round. Bacon.
Source : Webster's Unabridged Dictionary, 1913