from
The Collaborative International Dictionary of English v.0.48
Officer \Of"fi*cer\, n. [F. officier. See {Office}, and cf.
{Official}, n.]
1. 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.
[1913 Webster]
2. (U. S. Mil.) Specifically, a commissioned officer, in
distinction from a warrant officer or an enlisted man.
[1913 Webster]
{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.
[1913 Webster]