teacher

A teacher is a person who teaches, usually as a job at a school or similar institution.

I'm a teacher with 21 years' experience.

educator

An educator is a person who educates people.

mentor

A person's mentor is someone who gives them help and advice over a period of time, especially help and advice related to their job.

tutor

A tutor is someone who gives private lessons to one pupil or a very small group of pupils.

professor

A professor in a British university is the most senior teacher in a department.

A professor in an American or Canadian university or college is a teacher of the highest rank.

master

If you say that someone is a master of a particular activity, you mean that they are extremely skilled at it.

coach

A coach is someone who trains a person or team of people in a particular sport.

A coach is someone who gives people special teaching in a particular subject.