What is the longest palindrome word in English? [closed]

I want to know what the longest palindrome word is.

Detartrated.

Edit: surprise, surprise, Wikipedia has more:

The longest palindromic word in the Oxford English Dictionary is the onomatopoeic tattarrattat, coined by James Joyce in Ulysses (1922) for a knock on the door. The Guinness Book of Records gives the title to detartrated, the preterit and past participle of detartrate, a chemical term meaning to remove tartrates. Rotavator, a trademarked name for an agricultural machine, is often listed in dictionaries. The term redivider is used by some writers but appears to be an invented or derived term—only redivide and redivision appear in the Shorter Oxford Dictionary. Malayalam, an Indian language, is of equal length.

So let's see:

tattarrattat  (onomatopoeic)
detartrated
Rotavator     (trademark)
redivider     (disputed)
Malayalam

Not that long, but indisputable: racecar

(Though my browser does not care for the spelling. Did my 6th grade English teacher mislead me?)