B1
someone whose job is to help a person who has a more important job
Dictionary examples:
The professor's assistant mixed up the exam papers with takeout menus. (0.0)
The CEO's assistant accidentally ordered 1000 rubber ducks instead of office supplies. (0.0)
The chef's assistant mistook salt for sugar and ruined the birthday cake. (0.0)
an assistant editor/manager (28.9)
an administrative assistant (35.6)