educator

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One trained in teaching; a teacher.
• noun A specialist in the theory and practice of education.
• noun An administrator of a school or an educational institution.

from The Century Dictionary.

• noun One who or that which educates; specifically, one who makes a business or a special study of education; a teacher or instructor.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who educates; a teacher.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A person distinguished for his/her educational work
• noun A person who, or a thing which, educates
• noun A teacher
• noun A person that accepts responsibility for the educating process and educates by supporting and assisting an educand.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun someone who educates young people