A palindrome is a word, line, verse, number, or sentence that reads the same backward as it does forward. Like:

• Never odd or even.
• Dammit, I'm mad!

SotadesThe third century BCE Greek poet Sotades was said to have written such vulgar satires that King Ptolemy II had him sewn up in a sack and thrown into the sea, for insulting the king in one of his verses. But his coarse, vile verses must have been clever, for Sotades is reputed to have invented palindromes, which are sometimes called Sotadics in his honor.

Palindromes take their more common name from the Greek palin dromo, which means "running back again," and they are simply anagrams that read the same backward as forward.

Making palindromes has been a favorite word game since at least early Grecian times. English, with the largest and most varied vocabulary of all languages, offers the most viable ground for creating palindromes.

It is said that Sir Thomas Urquhart even invented a universal language based entirely on palindromes.

Thomas Urquhart

Another famous palindrome is the one English author Leigh Mercer wrote for Ferdinand de Lesseps, the man who began the Panama Canal:

A man, a plan, a canal: Panama!

A linguistics professor was lecturing to his class one day. "In English," he said, "A double negative forms a positive.  In some languages, though, such as Russian, a double negative is still a negative.  However, there is no language wherein a double positive can form a negative."

A voice from the back of the room piped up, "Yeah, right."