Collocations for department - noun

federal, government, state
Education Department, Health Department, etc.
fire, police (both AmE)
The Tokyo police department is clamping down on organized crime.

official, spokesman, spokesperson, spokeswoman
personnel (AmE), staff

department for
the Department for Transport (in the UK)

department of
the Department of Transportation (in the US)

accident and emergency (BrE), casualty (BrE), emergency (AmE), hospital, outpatient
design, finance, HR, legal, marketing, personnel, planning, publicity, sales, etc.
biology, English, science, etc.

head, manage, run
Staff criticized the way the history department was run.

join
A new member of staff has joined the department.

create, establish
contact
Contact our sales department for more information.

chair (esp. AmE), coordinator, head, manager
member (esp. AmE), staff

in a/the department
Complaints are dealt with in a different department.

within a/the department
to gain promotion within the department

department of
the Department of Planning

the head of a/the department, the head of department
a member of a/the department