What does the IHS mean in Catholic churches? You may notice the letters IHS on the cross, crucifix, stained glass window, tabernacle, altar, etc. within Catholic churches. What does IHS stand for? The IHS monogram is a shortened form of the Greek word for Jesus: ΙΗΣΟΥΣ. (Σ or "sigma" = "S") It is sometimes called the Christogram as the first three letters of Jesus' name. This symbol grew in popularity during the Middle Ages when devotion to the Holy Name of Jesus was on the rise. St. Ignatius of