ΙΧΘΥΣ (Ichthus) is an backronym/acrostic for “Ίησοῦς Χριστός, Θεοῦ Υἱός, Σωτήρ“, (Iēsous Christos, Theou Yios, Sōtēr), which translates into English as “Jesus Christ, Son of God, Savior”.
- Iota (i) is the first letter of Iēsous (Ἰησοῦς), Greek for “Jesus“.
- Chi (ch) is the first letter of Christos (Χριστός), Greek for “anointed”.
- Theta (th) is the first letter of Theou (Θεοῦ), Greek for “God’s”, the genitive case of Θεóς, Theos, Greek for “God”.
- Upsilon (y) is the first letter of (h)uios (Υἱός), Greek for “Son”.
- Sigma (s) is the first letter of sōtēr (Σωτήρ), Greek for “Savior”.
Legend and history surrounding the use of Ichthus and the fish symbol in early christianity abounds; however we know that there is definite historical usage, since Augustine explains it’s meaning in his “City of God”, and because it is found in ancient sites like Ephesus, in modern day Izmir Province, Turkey.