de‧ac‧ti‧vate /diːˈæktəveɪt, diːˈæktɪveɪt/ 
 verb [transitive] to switch something off, especially a piece of equipment, or to stop it from being used any more
 Antonym : activate: 
 You need to type in a code number to deactivate the alarm.
 You need to type in a code number to deactivate the alarm.  [TahlilGaran] Dictionary of Contemporary English ▲