de·activate \(ˈ)dē+\transitive verb Etymology:de- + activate 1.: to make inactive or ineffective 2. a.: to break up (as a military unit) by discharging or reassigning personnel : inactivate b.: to put (as a bomb or mine) in a condition that makes detonation impossible c.: to deprive of chemical activity < deactivate a compound by introducing substituents > < deactivate a catalyst or enzyme > • de·activation\(|)dē+\noun-s • de·activator\(ˈ)dē+\noun-s