TUTOR

noun

1. One who teaches another (usually called a student, learner, or tutee) in a one-on-one or small-group interaction.
2. A university officer responsible for students in a particular hall.
3. One who has the charge of a child or pupil and his estate; a guardian.

verb

1. To instruct or teach, especially an individual or small group.
2. To treat with authority or sternness.