De-energise means to remove energy or power from something. Antonyms for de-energize would mean the opposite, to assert energy or power into something. Some antonyms of de-energise include invigorate, energize, activate, animate, boost, empower, enliven, revitalize, stimulate, and vitalize. Invigorate refers to adding strength, energy, or vitality to something, whereas energize means to provide energy or power to something. Activate is to turn on or make something work effectively. Animate is to give life or energy to something. Boost is to increase something. Empower is to give someone the authority or power to do something. Enliven means to make more interesting or cheerful. Revitalize is to give new life, energy, or strength to something.