Definition: An adjunct professor is a part time instructor. Adjunct professors are hired by the class and by the semester. Usually they are not guaranteed work beyond the current semester and are not paid benefits. Adjunct professors work by contract so their responsibilities are limited to teaching the course they have been hired to teach. They are not required to conduct research or service activities. Typically adjunct professors are paid $2,000 to $4,000 per class, depending on the university. Many adjunct professors hold full-time jobs and teach to supplement their income. Some teach simply because they enjoy it. Other adjunct professors teach several classes at several institutions each semester in order to earn a living from teaching. Some academics argue that adjunct professors are taken advantage of because many so desire to keep a foot in academia despite heavy workloads and poor pay.