兼任 (jiān rèn): to hold a concurrent post; part-time; (in academia) adjunct

Teacher Wang at our school also serves as the head of the Chinese teaching research group; every week, besides teaching, he has to organize research activities.

After Engineer Zhang also took on the role of project manager, he has to handle technical issues during the day and coordinate team progress in the evening—he's extremely busy.

Professor Li teaches in the history department and also serves as a consultant for the university library, often recommending good books to students.

She works as a translator at a foreign trade company and on weekends also serves as an English tutor; she wants to save more money to study abroad.

The accountant at this small company also serves as the HR assistant; because they are short-staffed, the boss asked her to temporarily handle recruitment.