tutor

Short definition from Wiktionary

Noun

1. 1
   One who teaches another (usually called a student, learner, or tutee) in a one-on-one or small-group interaction.
2. 2
   A university officer responsible for students in a particular hall.
3. 3
   A homeroom.
4. 4
   One who has the charge of a child or pupil and his estate; a guardian.
5. 5
   A card that allows one to search one's deck for one or more other cards.

Verb

1. 1
   To instruct or teach, especially an individual or small group.
2. 2
   To treat with authority or sternness.
3. 3
   To fetch a card from one's deck.

Proper noun

1. 1
   A surname.