Monogram Celtic Cross Tattoo Design

The center of this cross is the monogram IHS, a popular Latinized monogram acronym from the Roman 3rd Century based on the GREEK letters Iota , the first letter of Greek for "Jesus"; Theta, the first letter of Theos , Greek for "God"; and Sigma , the first letter of Greek for "Savior".
Thus, IHS =  Jesus, God, Savior.
It could also be replaced with the initial or monogram of a loved one.