Palindromes

A palindrome is a word, phrase, number or other sequence that reads the same backwards as it does forwards. LEVEL reversed is LEVEL. KAYAK reversed is KAYAK. That is the whole definition, and it is a property of the spelling rather than of the meaning, which is why you can settle any case by writing the word out and reading it right to left.

The word arrived in English in the seventeenth century from the Greek palindromos, running back again, built from palin, again, and dromos, a running or a course. The same dromos gives us hippodrome and aerodrome.

Two conventions are worth stating because they decide what counts. Palindromes ignore case, so Level and LEVEL are the same test. And for phrases, they conventionally ignore spaces and punctuation, which is the only reason a sentence like “Madam, I'm Adam” qualifies at all. For single words, which is what this page lists, neither convention matters: the letters run the same way whatever you do with them.

7 letters, and 7 words get there: DEIFIED, HALALAH, REIFIER, REPAPER, REVIVER, ROTATOR, SEMEMES. Nothing in the dictionary is longer, and that is not a quirk of this particular word list. Palindromes get scarce fast because every letter you add has to be matched at the other end, so the constraint tightens with length while the supply of words thins out.

Of the seven, REVIVER and ROTATOR are the ones most people know. REPAPER and REIFIER are real but rare. DEIFIED is the one that turns up in puzzles. HALALAH is a unit of Saudi currency and SEMEMES are units of meaning in linguistics, and both are in the list for the same reason everything else is: they are in the dictionary and they read the same backwards.

Longer palindromes exist in English, but they leave the dictionary to do it. They are place names, invented words, or the chemical-sounding coinages people assemble to win the argument. The longest palindromic word in wide circulation is usually given as TATTARRATTAT, which James Joyce made up in Ulysses for the sound of a knock at the door, and which no dictionary carries.

If you want a handful rather than all 101, these are the ones that come up: LEVEL, RADAR, KAYAK, CIVIC, MADAM, REFER and ROTOR. Every one of them is five letters, which is no accident: five is long enough to feel deliberate and short enough that a word can still mirror itself, and the five-letter band holds 24 of the 101.

RACECAR is the interesting absence. It is the example almost everyone offers first, and it is genuinely a palindrome, but it is not in the list above. The public-domain word list this site searches spells it as two words, race car, so the single-word form never enters the dictionary. That is a fact about the word list rather than about the word, and it is the sort of thing this site would rather explain than quietly paper over.

The three-letter band is the largest at 50 words, and most of them are ordinary: BIB, DID, EYE, GAG, POP, WOW. If you are looking for a palindrome to use rather than to admire, that is where to look, because the short ones are the ones that fit into a puzzle grid or a sentence without anybody noticing the effort.

A palindromic sentence reads the same backwards once you drop the spaces, the punctuation and the capitals. That last part is doing a lot of work: without the convention, almost none of them would qualify, because the spaces never line up.

Two are genuinely famous and neither belongs to anyone: “A man, a plan, a canal, Panama” and “Madam, I'm Adam”. Both have been in circulation for well over a century. Strip them to letters and they do read the same both ways, which you can check for yourself in about ten seconds, and that is the only reason to believe them.

This page will not give you a list of them. Wordton holds a dictionary, which is a list of words, and a sentence is not in it. We could assemble a page of palindromic sentences from memory and present it as a set, and every other site that ranks for this phrase has done exactly that, but we would have no source for it and no way to tell you which ones are established and which ones somebody invented last year. Sentences are also unbounded in a way words are not: you can always make a longer one, so there is no complete list to publish even in principle.

Names like HANNAH and ELLE read the same backwards and do not appear in the list above. The reason is the same one that keeps RACECAR out: our dictionary is a list of common words, and proper nouns are not in it. A word list containing every given name would be a different kind of object and a far less useful one for the searching this site does.

So we cannot give you a checked list of palindromic names, and we are not going to improvise one. What we can tell you is the test, which is the same test as for any other word: write the name out, ignore the capital, and read it right to left. If it matches, it is a palindrome. That works for names we have never heard of as reliably as it works for HANNAH.

Several palindromic names do double as ordinary words, and those are in the list above, which is a coincidence of spelling rather than a rule. ANNA is an old Indian coin, OTTO is a variant spelling of attar, EVE is the day before, AVA is a Polynesian shrub, and BOB has a dozen meanings of its own. They earn their place as words, not as names.