The Collaborative International Dictionary
Officer \Of"fi*cer\, n. [F. officier. See Office, and cf. Official, n.]
One who holds an office; a person lawfully invested with an office, whether civil, military, or ecclesiastical; as, a church officer; a police officer; a staff officer. ``I am an officer of state.''
--Shak.-
(U. S. Mil.) Specifically, a commissioned officer, in distinction from a warrant officer or an enlisted man.
Field officer, General officer, etc. See under Field, General. etc.
Officer of the day (Mil.), the officer who, on a given day, has charge for that day of the guard, prisoners, and police of the post or camp; abbreviated O. D., OD, or O. O. D.
Officer of the deck, or Officer of the watch (Naut.), the officer temporarily in charge on the deck of a vessel, esp. a war vessel.