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.