Definition of "CO"
CO
noun
(military) Initialism of commanding officer.
(military) Initialism of commissioned officer.
(US, law enforcement) Initialism of corrections officer.
(US, law enforcement) Initialism of correctional officer.
(military) Initialism of conscientious objector.
(geology) Initialism of common-offset [method].
(poker) Abbreviation of cutoff.