Prayer for another or others. Intercession "brings before God the needs of others" (BCP, p. 857). Intercession is one of the seven principal kinds of prayer (BCP, p. 856). An intercessor is one who prays an intercessory prayer. See Intercessor.
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.