In biblical times, the word "evangelist" described one who proclaimed the gospel. What definition is given the word in latter-day revelation?
Here's answer to week's question
In latter-day revelation, an evangelist is defined as a patriarch. (D&C 107:39-53.) Joseph Smith taught: "An Evangelist is a Patriarch, even the oldest man of the blood of Joseph or of the seed of Abraham. Wherever the Church is established in the earth, there should be a Patriarch for the benefit of the posterity of the Saints. (HC 3:381.)"
Source: Bible Dictionary, 1979 LDS edition King James Bible, p. 668.