Vivificate refers to the act of enlivening, animating or invigorating something or someone. Its antonyms refer to the opposite of that, which is to diminish or weaken. One antonym for vivificate is "deaden," which means to make something less lively or active. Another antonym for vivificate is "stifle," which means to suppress or restrain something or someone. Similarly, "weaken" and "drain" can also be used as antonyms for vivificate, as they signify the opposite of invigorating or strengthening. In summary, the antonyms for vivificate suggest a decrease in vitality, energy or enthusiasm, rather than an increase.