The BCP uses the word "celebrant" to describe the priest or bishop who presides at the Holy Eucharist. The word "officiant" is used to describe the minister, lay or ordained, who presides at the Daily Offices. Most contemporary liturgical books use "president" or "presider" for both. "President" is used by the English Alternative Service Book, but it was felt to be too political to be used in the United States. Some feel that the word "celebrant" is inappropriate for the presider at the eucharist, since the entire congregation shares in the celebration. See Officiant.
President, Presider (liturgical)
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.