Officer

UK: /ˈɒfɪsə^r/ US: /ˈɔfəsɚ, ˈɑfə-/ ,(ô′fə sər, of′ə-)

WordReference Random House Learner's Dictionary of American English © 2026

of•fi•cer /ˈɔfəsɚ, ˈɑfə-/   n. [countable]

1. a person who holds a position of rank or authority in the armed services, esp. one holding a commission.
2. a member of a police department.
3. a person who is appointed or elected to a position of responsibility or authority in an organization.

See -oper-, -fac-.

WordReference Random House Unabridged Dictionary of American English © 2026

of•fi•cer  (ô′fə sər, of′ə-), n. 

1. a person who holds a position of rank or authority in the army, navy, air force, or any similar organization, esp. one who holds a commission.
2. a member of a police department or a constable.
3. a person licensed to take full or partial responsibility for the operation of a merchant ship or other large civilian ship; a master or mate.
4. a person appointed or elected to some position of responsibility or authority in the government, a corporation, a society, etc.
5. (in some honorary orders) a member of any rank except the lowest.
6. [Obs.] an agent.

v.t. 

7. to furnish with officers.
8. to command or direct as an officer does.
9. to direct, conduct, or manage.

• Medieval Latin officiārius, equivalent. to Latin offici(um) office + -ārius -ary; see -er², -ier²
• Anglo-French; Middle French officier
• Middle English 1275–1325

of•fi•ce•ri•al  (ô′fə sēr′ē əl, of′ə-), adj.  of′fi•cer•less, adj. 
of′fi•cer•ship′, of′fi•cer•hood′, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

officer / ˈɒfɪsə/ noun

1. a person in the armed services who holds a position of responsibility, authority, and duty, esp one who holds a commission
2. See police officer
3. (on a non-naval ship) any person including the captain and mate, who holds a position of authority and responsibility: radio officer, engineer officer
4. a person appointed or elected to a position of responsibility or authority in a government, society, etc
5. a government official: a customs officer
6. (in the Order of the British Empire) a member of the grade below commander

verb (transitive)

1. to furnish with officers
2. to act as an officer over (some section, group, organization, etc)