professor

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

• noun A college or university teacher who ranks above an associate professor.
• noun A teacher or instructor.
• noun One who professes.

from The Century Dictionary.

• noun One who professes; one who openly declares or makes profession of specific belief or views, of adherence to a certain course of action or way of life, or of knowledge or skill in any particular calling.
• noun One who makes open profession of religious faith and conversion, and attaches himself to some religious denomination.
• noun A public teacher in a university, especially one to whom this title has been formally granted.
• noun In a loose use, any one who publicly teaches or exercises an art or occupation for pay, as a dancing-master, phrenologist, balloonist, juggler, acrobat, boxer, etc.
• noun The name of an artificial fly used in angling.

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

• noun One who professed, or makes open declaration of, his sentiments or opinions; especially, one who makes a public avowal of his belief in the Scriptures and his faith in Christ, and thus unites himself to the visible church.
• noun One who professed, or publicly teaches, any science or branch of learning; especially, an officer in a university, college, or other seminary, whose business it is to read lectures, or instruct students, in a particular branch of learning; as a professor of theology, of botany, of mathematics, or of political economy.

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

• noun A teacher or faculty member at a college or university.
• noun A higher ranking for a teacher or faculty member at a college or university. Abbreviated Prof.
• noun An honorific title for a higher ranking teacher. (Capitalised)
• noun archaic One who professes.
• noun US, slang A pianist in a saloon, brothel, etc.
• noun The puppeteer who performs a Punch and Judy show; a Punchman.

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

• noun someone who is a member of the faculty at a college or university