A 5-by-5 palindromic word square is one in which the first word is a reversal of the fifth word, the second is a reversal of the fourth, and the third is a palindrome. The most famous of these squares, the Latin one given at the right, can be translated "Arepo the begetter (or sower) holds the wheels with care". It has been found on ancient walls and on amulets for safe childbirth; there is an extensive literature discussing its religious or mystical significance (see, for example, pp. 207-210 of Dmitri Borgmann's Language on Vacation (Scribner's, 1965)).
McIlroy, M. D.
"5-by-5 Palindromic Word Squares,"
Word Ways: Vol. 9
, Article 3.
Available at: http://digitalcommons.butler.edu/wordways/vol9/iss4/3