In poetry, a palindrome (from the Greek palindromos, meaning running back again) is a poem, line, or sentence that reads the same both forward and backward, either letter by letter or word by word.
One early example, attributed to Gregory of Nazianuzus (329–389 A.D.), is in Latin:
nipson anomemata me monan opsin
This translates to,
Wash my transgressions, not only my face.
There are also some well-known examples in English, such as these two attributed to Napoleon:
Madam, I’m Adam.
Able was I ere I saw Elba.
In Latin, reciprocus versus refers to a line that scans the same both forward and backward, such as this one by Hart Crane:
Twilight, stiller than shadows, fall.