department

UK: /dɪˈpɑː^rtmənt/ US: /dɪˈpɑrtmənt/ ,(di pärt′mənt)

WordReference Random House Learner's Dictionary of American English © 2025

de•part•ment /dɪˈpɑrtmənt/   n. [countable]

1. a part of a larger structure; a division or branch, as of business:
   assigned to a new department.
2. [usually singular] one's special area of activity, expertise, or responsibility:
   Tax questions are just not my department.

de•part•men•tal /dɪpɑrtˈmɛntəl, ˌdipɑrt-/  adj. See -par-.

WordReference Random House Unabridged Dictionary of American English © 2025

de•part•ment  (di pärt′mənt), n. 

1. a distinct part of anything arranged in divisions; a division of a complex whole or organized system.
2. Government one of the principal branches of a governmental organization:
   the sanitation department.
3. Government (cap.) one of the principal divisions of the U.S. federal government, headed by a Secretary who is a member of the President's cabinet.
4. Business a division of a business enterprise dealing with a particular area of activity:
   the personnel department.
5. Business a section of a retail store selling a particular class or kind of goods:
   the sportswear department.
6. Education one of the sections of a school or college dealing with a particular field of knowledge:
   the English department.
7. Government one of the large districts into which certain countries, as France, are divided for administrative purposes.
8. a division of official business, duties, or functions:
   judicial departments.
9. a sphere or province of activity, knowledge, or responsibility:
   Paying the bills is not my department.
10. Military (usually cap.) [U.S. Army.] (formerly) a large geographical division of the U.S. or its possessions as divided for military and defense purposes:
    the Hawaiian Department.

• French département, equivalent. to départ(ir) (see depart) + -ment -ment
• 1730–35

de•part•men•tal  (di pärt men′tl, dē′pärt-), adj.  de•part•men′tal•ly, adv. 
Synonyms

• 1. branch, bureau, section, unit, segment.

Collins Concise English Dictionary © HarperCollins Publishers::

department / dɪˈpɑːtmənt/ noun

1. a specialized division of a large concern, such as a business, store, or university: the geography department
2. a major subdivision or branch of the administration of a government
3. a branch or subdivision of learning: physics is a department of science
4. a territorial and administrative division in several countries, such as France
5. a specialized sphere of knowledge, skill, or activity: household budgeting is my wife's department

Etymology: 18th Century: from French département, from départir to divide; see depart

departmental / ˌdiːpɑːtˈmɛnt^əl/ adjective