noun
chief; head; manager; person in charge
A title or role for someone in charge of a section, team, or project. Often used in workplace hierarchies below 課長 (section chief).
彼は営業部の主任に昇進した。
He was promoted to chief of the sales department.
主任がプロジェクトの進捗を報告した。
The person in charge reported on the project's progress.