[‘ The condition of being overshadowed or darkened; a darkening or blacking-out; shade or gloom.']
Etymology: < post-classical Latin /obtenebration-, /obtenebratio obscuration, darkening (5th cent.) < /obtenebrat-, past participial stem of /obtenebrare/ obtenebrate v. + /-io/ -ion suffix1. Compare Middle French /obtenebration (16th cent.). Compare later /tenebration/ n. at tenebrate adj. Derivatives.
/Obs./
The condition of being overshadowed or darkened; a darkening or blacking-out; shade or gloom.
1626 Bacon /Sylua Syluarum/ §725 In every Megrim, or Vertigo, there is an Obtenebration joyned with a Semblance of Turning Round.
1672 T. Gale /Court of Gentiles: Pt. I/ (ed. 2) iii. x. 99 The Obtenebration of the Sun, Moon, Stars, and Light.
1881 E. M. Boddy /Hist. Salt/ ii. 25 The dense obtenebration with which the object is surrounded.