The term "professional student" typically refers to someone who is pursuing an advanced degree and has dedicated their life to academic study. This person may be focused on achieving a high level of expertise in a particular field, and may have put off other aspects of adult life such as work or family in order to continue their education. In this sense, the phrase "professional student" is not meant to be pejorative but rather describes someone who has made academia their primary focus and pursued it with dedication and commitment.