Impetrate
To petition or beseech; to obtain by entreaty. Impetrative prayer asks God to accomplish what has been requested. Impetration relies on God's loving generosity and willingness to answer prayer. In eucharistic theology, impetrative sacrifice entreats God's favor, and impetration is one of the purposes of the celebration of the eucharistic sacrifice.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from “An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians,” Don S. Armentrout and Robert Boak Slocum, editors.