The opposite or antonyms for the word "make inert" are activate, enliven, energize, animate, and stimulate. These words refer to the process of making something active, alive, or productive. To activate something means to put it in motion or to turn it on, while enlivening refers to making something more engaging, interesting or exciting. Energizing involves providing something with energy, power or strength, and animating means bringing life or spirit to something. Stimulating, on the other hand, means to arouse, provoke or excite. Therefore, the antonyms for "make inert" are words that are opposite in meaning but represent a dynamic and powerful energy that is unleashed or activated.