One who proclaims good news, either by preaching or writing. There were originally evangelists or preachers who, without being fixed to any church, preached wherever they were led by the Holy Spirit, like some missionaries in our own day, Ephesians 4:11. Such was Philip, Acts 21:8. Timothy also is exhorted to "do the work of an evangelist," because they were the writers of the four gospels, which bring to all men the glad tidings of eternal salvation.
These dictionary topics are from American Tract Society Bible Dictionary published in 1859. Public Domain, copy freely.
Rand, W. W. "Entry for 'EVANGELIST'". "American Tract Society Bible Dictionary".