semordnilap
/səˈmɔːdnɪlæp/
Etymology
A reverse spelling of palindromes. "Semordnilap", according to author O. V. Michaelsen in his 1997 book Words at Play, was probably first used by recreational linguist Dmitri Borgmann, cited by Martin Gardner in the revised edition of Charles Carroll Bombaugh's Oddities and Curiosities of Words and Literature (1961) http://books.google.com/books?id=f4kNAQAAIAAJ&q=borgmann. The underlying concept (but not the term) is found at least as far back as Lewis Carroll's Sylvie and Bruno (1889). Semordnilap is also autological; that is, it is a self-describing word, as the word semordnilap is itself a semordnilap.
Why this word is great
SEMORDNILAP — [Noun] A word, phrase, or sentence that forms another distinct word, phrase, or sentence when its letters are reversed. A reverse spelling of 'palindromes', coined by recreational linguist Dmitri Borgmann, as cited by Martin Gardner in the revised edition of Charles Carroll Bombaugh's 'Oddities and Curiosities of Words and Literature' (1961). Unlike 'palindrome' (which mirrors itself, static and self-contained) or 'anagram' (which scatters letters like dice), a semordnilap is a linguistic Janus, revealing its twin only when read in reverse. It is 'stressed' becoming 'desserts,' 'diaper' unfolding into 'repaid,' or 'live' twisting into 'evil'—a quiet reminder that meaning, like perspective, depends entirely on which way you look.
noun
- A word, phrase, or sentence that has the property of forming another word, phrase, or sentence when its letters are reversed. A semordnilap differs from a palindrome in that the word or phrase resulting from the reversal is different from the original word or phrase.“[He] then goes on to credit us with giving him some of the best examples of semordnilaps.”