acolyte

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A person who assists the celebrant in the performance of liturgical rites.
• noun A devoted follower or attendant.

from The Century Dictionary.

• noun One who waits on a person; an attendant; an assistant.
• noun In the Roman Catholic Church, one ordained to the fourth and highest of the minor orders, ranking immediately below the subdeacon. See orders.
• noun In astronomy, an attendant or accompanying star or other heavenly body; a satellite.
• noun Sometimes written acolyth, and formerly also acholithite, acolythe, acolythist, acolothist.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Eccl.) One who has received the highest of the four minor orders in the Catholic church, being ordained to carry the wine and water and the lights at the Mass.
• noun One who attends; an assistant.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun ecclesiastical One who has received the highest of the four minor orders in the Catholic Church, being ordained to carry the wine, water and lights at Mass.
• noun An attendant, assistant or follower.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun someone who assists a priest or minister in a liturgical service; a cleric ordained in the highest of the minor orders in the Roman Catholic Church but not in the Anglican Church or the Eastern Orthodox Churches