pro·fes·sor 
(prə-fĕsər)
(prə-fĕsər)n.
1.
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.
pro′fes·sori·al·ly adv.
pro·fessor·ship′ n.