This is a variation of Abarcadraba.

Consider all possible valid English words having at least 4 letters and at most 13 letters that satisfies the following conditions:

• Each word begins and ends with the same letter, and:
• Reversing the letters we obtain another valid English word, and:
• None of the words can be palindromes, and:
• None of the words can be plurals, proper nouns or abbreviations, and:
• None of the words can be hyphenated like A-bomb, X-ray etc.

What are the respective shortest word and the longest word that satisfy all the given conditions? Does there exist any valid English word having more than 13 letters that satisfies all the conditions?

To add to Charlie's list:

amora - aroma ¹
circ - cric ²
daud - duad ³
lapel - lepal ²
rater - retar ⁴
skeets - steeks ^3,5
splits - stilps ²
sports - strops ⁵


1. The noun amora is defined as one of a group of rabbis around 500 CE whose teachings are found in the Mishnah. In this sense it is often capitalized (especially in American English). Yet, it can also be a common noun (not capitalized) meaning a (rabbinical) lecturer's assistant. 
2. Circ, cric, lepal and stilps are found in early-20th century editions of English dictionaries, and may be considered obsolete, yet may possibly also be considered valid English words.
   circ : an amphitheatrical circle for sports; a circus
   cric : the inward turning ring which condenses a lamp's flame
   lepal : (Botany) a sterile transformed stamen
   stilps :  walks with stilts or crutches, or long, high steps; stalks
3. Daud, "a lump or chunk of something", and skeets "shuts, closes", are considered chiefly Scottish. They can be found in some English dictionaries, thus they should be considered valid English words. 
4. The prefix "re-" can be attached to many terminative verbs where the action can be performed again, such as to "retar the roof".  Questionable pairs of this sort are "reveler - relever" and "referer - rerefer".
5. The word pair, like sleets - steels, snaps - spans, snips - spins, spoons - snoops, spots - stops, stows - swots, and struts - sturts, are words that can be both plural nouns and 3rd person singular present verbs. As they can be verbs, they were not excluded from the list. (Note: I did not find sturts as a verb except in some of the "obsolete" word references - (sturt : "to vex; to annoy; to startle"). The word,  as a noun,  is listed in some of the more modern dictionaries.) Another word pair of this sort is spits - stips, yet the verb stips (a clipping of "stipulates") was not found in any standard dictionary but only the open content dictionary of Wiktionary, thus may not be considered a valid word. The verb steeks is considered a Southern US or British word, thus, though uncommon in many parts of the English speaking world, it would be a valid word.  

Edited on January 24, 2012, 3:31 am

Posted by Dej Mar on 2012-01-23 19:48:10