Source : Webster's Revised Unabridged Dictionary (1913)

Obsecration \Ob"se*cra"tion\, n. [L. obsecratio: cf. F.
   obsecration.]
   1. The act of obsecrating or imploring; as, the obsecrations
      of the Litany, being those clauses beginning with ``By.''
      --Bp. Stillingfeet. --Shipley.

   2. (Rhet.) A figure of speech in which the orator implores
      the assistance of God or man.