Palindrome – A word, a line, a sentence, or a group of sentences (sometimes in verse) that reads the same backward and forward.
A palindrome is commonly thought of as a word, phrase or sentence that reads alike both backward and forward. The word, derived from the Greek palindromia, literally means a running back again. In poetry and prose, the concept is expanded to multiple lines (or stanzas) where the lines in the first half of the poem are repeated, in reverse order, in the second half. What lends the palindrome its power is the shift in emphasis or meaning when the lines are repeated, which allows the poet to give a different perspective in each half of the poem. (from In Fine Form – the Canadian Book of Form Poetry ed. Kate Braid and Sandy Shreve.)