What is the word?

[chappie]

There is a word for a word that is spelt the same backwards as forwards (eg MADAM).

What is the word, please? It's driving me mad trying to think of it. Anyone know?

PS: Posted in the wrong category? Pfft!!!!

PPS: Can anyone think of any more examples?

[pastafreak]

ooooooooeeeeeeeeeerrrr!!