In rhetoric, a palindrome is a word, number, phrase, or other sequence of characters which reads the same backwards as forwards.
The word palindrome was introduced by Henry Peacham, the English poet and writer, in 1638. It is derived from the Greek roots “πάλιν”, meaning “again” and “δρóμος” meaning “way”, or “direction”. However, there is a different word is used in Greek, “καρκινικός” “carcinic”, which literally means “crab-like”, to refer to letter-by-letter reversible writing.
English has a surfeit of palindrome words, such as eye, redivider, deified, civic, radar, level, rotor, kayak, reviver, racecar, madam, and refer. Palindromic sentences, on the other hand, are rare. A John Taylor coined one in 1614: : “Lewd did I live, & evil I did dwel.” In 1848, a certain “J.T.R.”, who is still unknown, coined, “Able was I ere I saw Elba”. This became famous after it was implausibly attributed to Napoleon Bonaparte, alluding to his exile on Elba. Another famous palindrome, for its time, was from 1948: “A man, a plan, a canal – Panama.” The authorship is uncertain. Other examples include, “Dogma I am God”, “Mr. Owl ate my metal worm”, “Do geese see God?”, and “Was it a car or a cat I saw?”. In many cases, punctuation, capitalisation, and spaces are ignored. Some, such as “Rats live on no evil star”, “Live on time, emit no evil”, and “Step on no pets”, include the spaces in the palindrome.
Another form of palindrome are word-unit palindromes. Word-unit palindromes are where the unit of reversal is the word. For example, “Is it crazy how saying sentences backwards creates backwards sentences saying how crazy it is?”. James Albert Lindon, the English puzzle enthusiast and poet, made word-unit palindromes popular in the recreational linguistics community in the 1960s.
The longest palindromic word in the Oxford English Dictionary is the onomatopoeic “tattarrattat”. This was coined by James Augustine Aloysius Joyce, the Irish novelist, in “Ulysses”, in 1922. It referred to 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. “Redivider” is used by some writers, but appears to be an invented or derived term since only “redivide” and “redivision” appeared in the Oxford Dictionary. The word, “Malayalam”, referring to a South Indian language, is of equal length.
English palindromes of notable length include mathematician, Dr. Peter John Hilton’s, “Doc, note: I dissent. A fast never prevents a fatness. I diet on cod”. and Scottish poet, Alastair Reid’s “T. Eliot, top bard, notes putrid tang emanating, is sad; I'd assign it a name: gnat dirt upset on drab pot toilet.”
In contrast, we have the anadrome, or emordnilap. “Emordnilap” is simply “palindrome” backwards. They refer to words whose spelling is derived by reversing the spelling of another word. This makes it a specific type of anagram. “Anadrome” is derived from Ancient Greek “ανα”, meaning “backwards”, and “δρóμος” meaning “way”, or “direction”. Anadromes are also called levidromes, or reverse pairs. Examples of anadromes include the following:
Abut and tuba
Avid and diva
Bard and drab
Bats and stab
Brag and garb
Decal and laced
Deeps and speed
Doom and mood
Edit and tide
Flow and wolf
Gnat and tang
Maws and swam
Redraw and warder
Remit and timer
Sloops and spools
Snaps and spans
Sports and strops
Way and yaw