"Chi-Rho" is a term that refers to a symbol consisting of the first two letters of the word Christ in Greek. This symbol has been used as an emblem of early Christianity and has been represented in various forms throughout history. There are many synonyms for the term "Chi-Rho," such as "Christogram," "Labarum," and "PX symbol," among others. Each of these synonyms represents the symbol in distinctive ways. For instance, "Labarum" is a symbolic representation of the Chi-Rho used by the Roman emperor Constantine, while PX symbol is an abbreviation of the Greek word "paschal," meaning "of or relating to Easter".