A suffix is a letter or letters added at the end of a word to add meaning to that word. In the word “Christian” the suffix is “-ian,” which is a variant of the suffix “-an” and it means “pertaining to.” When it is added at the end of a word, it refers to a person who practices or is related to that noun. Therefore, “Christian” refers to a person that practices Jesus Christ's teaching, or that relates to Jesus Christ or his teachings.