Palindrome: A word, phrase, number, or other sequence of symbols or elements, whose meaning may be interpreted the same way in either forward or reverse direction. From the Greek palindromos running back again, from palin back, again + dramein to run. First known use: circa 1629.
A few examples:
Aibohphobia: Term used to describe the fear of palindromes.
Madam, I’m Adam: The first pick-up line ever used.
Saippuakivikauppias: Per Guinness World Records, the longest known palindromic word at 19 letters; which is Finnish for a dealer in lye (caustic soda).
In words alas drown I: The overwhelmed NaNoWriMo’er.