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 preterite 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", a language of southern India, is of equal length.