a. A college or university teacher who ranks above an associate professor.
b. A teacher or instructor.
2. One who professes.
[Middle English professour, from Old French professeur, from Latin professor, from professus, past participle of profitērī, to profess; see PROFESS.]
pro′fes·sori·al (prō′fĭ-sôrē-əl, prŏf′ĭ-) adj.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.