deactivate - remove from active military status or reassign; "The men were deactivated after five years of service"

demob, demobilise, demobilize - retire from military service

demobilise, demobilize, inactivate - release from military service or remove from the active list of military service

cannon - fire a cannon

let go, let go of, release, relinquish - release, as from one's grip; "Let go of the door handle, please!"; "relinquish your grip on the rope--you won't fall"