This is the 804th most frequent Russian word.
начальник
"Начальник" means "boss" or "superior."
Here, 'начальник' is used to refer to a direct supervisor or manager in a workplace.
Мой начальник дал мне новый проект.
My boss gave me a new project.
In this sentence, 'начальник' denotes the leader or head of a specific department, in this case, the sales department.
Начальник отдела по продажам провел встречу.
The head of the sales department held a meeting.
Here, 'начальник' is generic and refers to any superior or authority figure in a professional setting.