%obsecration%

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. [ 1913 Webster ]

2. (Rhet.) A figure of speech in which the orator implores the assistance of God or man. [ 1913 Webster ]