evangelist

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

• noun Any of the authors of the four Gospels in the New Testament, traditionally identified by the names Matthew, Mark, Luke, and John.
• noun One who practices evangelism, especially a Protestant preacher or missionary.
• noun One who promulgates or promotes something enthusiastically.

from The Century Dictionary.

• noun In the New Testament, a class of teachers next in rank to apostles and prophets, but probably not constituting a permanent order.
• noun In church hist., an itinerant preacher who travels from place to place, according to opportunity or requisition, in contradistinction to the pastor or teacher, who is settled in one place and instructs the people of a special charge.
• noun One of the writers of the four evangels or Gospels.
• noun In the Mormon Ch., an ecclesiastical official, also called a patriarch, whose duty it is “to bless the fatherless in the Church, foretelling what shall befall them and their generation. He also holds authority to administer in other ordinances of the Church” (Mormon Catechism, xvii.).

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

• noun A missionary preacher sent forth to prepare the way for a resident pastor; an itinerant missionary preacher.
• noun A writer of one of the four Gospels (With the definite article).
• noun A traveling preacher whose efforts are chiefly directed to arouse to immediate repentance.

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

• noun Christianity An itinerant or special preacher, especially a revivalist.
• noun A preacher of the gospel.
• noun biblical A writer of a gospel, especially the four New Testament Gospels (Matthew, Mark, Luke, and John), usually Evangelist.
• noun A person who first brought the gospel to a city or region.
• noun A patriarch
• noun A person marked by extreme enthusiasm for or support of any cause, particularly with regard to religion.

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

• noun a preacher of the Christian gospel
• noun (when capitalized) any of the spiritual leaders who are assumed to be authors of the Gospels in the New Testament: Matthew, Mark, Luke, and John