An acrostic is a poem or other form of writing in which the first letter, syllable or word of each line, paragraph or other recurring feature in the text spells out a word or a message. As a form of constrained writing, an acrostic can be used as a mnemonic device to aid memory retrieval. A famous acrostic was made in Greek for the acclamation JESUS CHRIST, GOD'S SON, SAVIOUR (Greek: Ιησούς Χριστός, Θεού Υιός, Σωτήρ; Iesous CHristos, THeou Yios, Soter — ch and th being each one letter in Greek). The initials spell ICHTHYS (ΙΧΘΥΣ), Greek for fish – hence the frequent use of the fish as a symbol for Jesus Christ from the early days of Christianity to the present time.[1]
Combining the late Greek ákros ("top"), and stíchos, ("verse") formed akróstichis, the origin of the English word acrostic.