mis·sion·ar·y 
(mĭshə-nĕr′ē)
(mĭshə-nĕr′ē)n. pl. mis·sion·ar·ies
1. One who is sent on a mission, especially one sent to do religious or charitable work in a territory or foreign country.
2. One who attempts to persuade or convert others to a particular program, doctrine, or set of principles; a propagandist.
adj.
1. Of or relating to missions or missionaries.
2. Engaged in the activities of a mission or missionary.
3. Tending to propagandize or use insistent persuasion: missionary fervor.