Jesus our Savior. Greek title found in early Christian inscriptions.
In uncial Greek script, the first three letters (iota, eta and sigma) look like IHC, but the Latin transliteration was IHS because Latin I is the equivalent of iota, H was used to transliterate eta since there was no other one-letter equivalent for the Greek eta in Latin (the sound is one letter in Greek, but a two-letter diphthong in Latin), and Latin S is the Latin transliteration for sigma.