How should I say the "relationship" between the professor and student in America?

When I apply for the admission to the graduate school in America, I need to provide the "Recommendation Provider" in the online system.

• What should I write when I am asked "relationship to you"?
• Are there any specific group of words for such relationship?
• Is "teacher-student" a proper word?
• What if the professor is not only my teacher but also the thesis adviser? How should I write the relationship?

"Professor" is his relationship to you. "Professor & thesis adviser", or "Professor/Adviser" would cover the rest.

I don't know of a better word, unless you are looking for something like "mentor". That might be helpful if you were writing a recommendation for him, but not so much for you.

Strictly speaking, the name of the relationship would be something like:

• Tutelage
• Mentorship
• Apprenticeship
• Guidance
• Instruction, etc.

However, when asked for their "relationship to you", you are expected to only give their title or role such as "professor" or "thesis advisor".