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 detartrated, the past tense of detartrate, a somewhat contrived chemical term meaning to remove tartrates. Rotavator, a trademarked name for an agricultural machine, is often listed in dictionaries. The term redivider (i.e. someone or something that redivides) is used by some writers but appears to be an invented term - only redivide and redivision appear in the "Shorter Oxford Dictionary". Malayalam, an Indian language, is of equal length (strictly, this name should be spelt either Malayaalam or Malay\u0101lam, as the next to last vowel is long.) Another aspect of the word "malayalam" is that it stays a letter palindrome if it is written in any phonetic script like devnagari.

The Finnish word saippuakivikauppias (soap-stone vendor) is claimed to be the world's longest palindromic word in everyday use. A meaningful derivative from it is saippuakalasalakauppias (soapfish bootlegger). An even longer effort is saippuakuppinippukauppias (soapdish batch seller) Koortsmeetsysteemstrook (fever measuring system strip) is probably the longest palindrome in Dutch, and Kuulilennuteetunneliluuk (bullet flightway tunnel hatch) is the longest palindrome in Estonian.