Tillich is a name that is not common in everyday vocabulary, so there are no widely recognized synonyms for this word. However, some possible alternatives could be phrases that describe the characteristics of Tillich's work such as "theology of culture" and "existentialist theology." His ideas are often associated with terms such as "ultimate concern," "ground of being," and "transcendence." These phrases could be used in place of Tillich to convey similar meanings. It is important to note that Tillich's work, being unique and innovative, cannot be fully replaced by any set of synonyms.