Trainer
- An experienced missionary assigned to be a new missionary's first companion, responsible for teaching them how to do missionary work day to day.
The trainer/greenie relationship is spoken of in family terms: mission slang often calls the trainer the new missionary's "father" (or "mother" for sisters) and the greenie their "son" or "daughter," with the whole chain of trained missionaries forming a "mission family" or "genealogy." A good trainer sets the tone for a new missionary's entire mission, which is why the assignment is taken seriously by leadership.