The longest known palindrome – a word that reads the same backwards or forwards – in any language is the 19-letter word saippuakivikauppias, which is Finnish for "a dealer in lye", meaning a seller of soap stone. The longest palindrome in the Oxford English Dictionary is the 12-letter tattarrattat, a nonce word (invented for a particular event or occasion) meaning rat-a-tat. The Irish author James Joyce used the word in Ulysses (1922): "I knew his tattarrattat at the door."...

The longest known palindrome – a word that reads the same backwards or forwards – in any language is the 19-letter word saippuakivikauppias, which is Finnish for "a dealer in lye", meaning a seller of soap stone. The longest palindrome in the Oxford English Dictionary is the 12-letter tattarrattat, a nonce word (invented for a particular event or occasion) meaning rat-a-tat. The Irish author James Joyce used the word in Ulysses (1922): "I knew his tattarrattat at the door."

Do good? I? No! Evil anon I deliver. I maim nine more hero-men in Saginaw, sanitary sword a-tuck, Carol, I -- lo! -- rack, cut a drowsy rat in Aswan. I gas nine more hero-men in Miami. Reviled, I (Nona) live on. I do, O God!