-ist

1. 1. One that performs a specified action: lobbyist.
   2. One that produces, makes, operates, plays, or is connected with a specified thing: novelist.
2. A specialist in a specified art, science, or skill: biologist.
3. An adherent or advocate of a specified doctrine, theory, or school of thought: anarchist.
4. One that is characterized by a specified trait or quality: romanticist.

[Middle English -iste, from Old French, from Latin -istēs, -ista, from Greek -istēs, agent n. suff.]