His groundbreaking research led to his appointment as the department chair and a significant increase in responsibilities.

appointment 是动词 appoint 的名词形式，由 appoint（任命）加上名词后缀 -ment 构成。appoint 本身由前缀 ap-（表示"朝向"）和 point（指向）组成，字面意思是"指向某人担任某个职位"。 appointment 在这里指"正式任命担任某个职位"的行为或结果，即"被任命为系主任"这一事实。