The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Palindrome: From the Greek for “running back again,” writing in which characters, such as letters or numbers, are exactly the same whether read forward or backward (ignoring punctuation and spaces). Word palindromes are lines or sentences that read the same way whether the words are read forward or backward. Given that the letters, numbers, or words on either side of the midpoint of a palindrome mirror one another, a palindrome is a type of chiasmus.
EXAMPLES: Words such as civic, racecar, and radar are palindromes, as is the sentence “Madam, I’m Adam” and the apocryphal line falsely attributed to Napoleon, “Able was I ere I saw Elba.” Examples of numeric palindromes include 11, 202, and 3553; furthermore, adding a number (e.g., 47) to its reverse form (e.g., 74) often results in a number that is itself a palindrome (e.g., 121). An example of a word palindrome is the sentence “First ladies rule the state and state the rule ’Ladies first.’”
Adah Price, one of the characters and narrators in Barbara Kingsolver’s novel The Poisonwood Bible (1998), makes frequent use of palindromes, such as “Amen, enema” and “Evil, all its sin is still alive.”