I am a great fan of wordplay, the highest form of which is the palindrome.
A palindrome is a word or phrase that reads the same when its letters are reversed (without regard to punctuation or spacing). The canonical example of a palindrome is "Madam, I'm Adam." Consider also "noon," "evil olive" and "too hot to hoot."
So that aficionados of this art form might have a ready way to refer to their field of study, I have coined the term ygology, meaning the study of palindromes. (Andrew Grantham also invented the word independently.) Note that one who practices ygology is therefore an ygologist, and not a tsigologist or any other such nonsense.
The word "palindrome" come from the Greek palindromos, meaning "running back again." (At least, that's what Merriam-Webster OnLine says. I don't know Greek, so I don't know for sure). This is, of course, the etymology of ygology.
A little-known synonym for the word "palindromic" is "cancrine," which also means "crab-like." I learned this from A.Word.A.Day.
An interesting mathematics problem involves palindromic numbers.
In molecular biology, a palindrome is a little different. It is a nucleotide sequence whose second half is the complement of the reverse of the first. Like CATATATG. There's a little more about that on my page on typogenetics.