The phrase "add spice" means to add excitement or interest to something. There are many synonyms for this phrase, including "spice up," "liven up," "enliven," "embellish," "enhance," "brighten," "revitalize," "stimulate," "animate," "galvanize," and "energize." Each of these synonyms implies a different level or type of change, from simply adding a small amount of interest to a significant transformation. Using a variety of synonyms can help to add nuance and depth to your writing, ensuring that you convey exactly the right message. So the next time you want to add spice to your words, consider trying out one of these exciting alternatives.