Following on from CodeNewbie's question "From Puzzling to Stack Exchange", I thought I would set a problem of my own using the same rules:

Rules:

• In any move, you can either replace a letter, add a letter, remove a letter, split a word or combine two words. These are the five valid moves, and only one of these can be applied in a move.

• After each move, each of the resulting words must be valid by itself, even if it makes no sense as a phrase. To level the playing field, only words found on Dictionary.com are considered valid. No proper nouns, abbreviations, prefixes or suffixes allowed. (However, words like jack, john, jane etc. are allowed as they are used as common nouns too.) Alternate spellings and archaic words are permitted, but words referring to specific persons, places or events are not valid.

• You may only add a letter to an existing word, but a new letter (such as a or I) cannot create a new word separately. Likewise, you cannot drop a letter from a one-letter word to remove it altogether.

The problem is that two of the words I chose Perfect and Answer appeared to be word islands. By this I mean that there doesn't appear to be any way to move from those words to any other words following the rules above (except, of course for the trivial case of adding an S to the end which doesn't help the transition to anything else).

Question

What is the shortest word that anyone can find which is also a word island? (I'll accept answers where it is one of a pair of words where the only valid moves are back and forwards between them)

Of course, I would be glad to hear if my two examples are not, in fact, islands after all.

• dictionary.com limiter is the mind killer, searched persect and found this speclab.com/compound/c5264553.htm so if ditching the dictionary.com limitation then would perfect still dead-end? Aug 19, 2015 at 18:43
• Where does COBOL fall on the acceptance spectrum. It's on dictionary.com but it's sort of an abbreviation Aug 19, 2015 at 18:52
• Perfect has two words besides adding the 's'. Perfecta and Perfecto are both on Dictionary.com. Perfecta is probably the better choices for creating longer chains, since your second move can be splitting it into "perfect a", but perfecto looks to be a more "legitimate" word. Aug 19, 2015 at 18:58
• @NeedAName if you are suggesting COBOL as a answer, you can drop the B to make cool. Aug 19, 2015 at 19:10
• I'm not, I was looking at OBOE/OBOL Aug 19, 2015 at 19:10

Using the TWL 2006 wordlist, the shortest isolani (1-word islands) are 4 letters long: asci enuf lynx pfft sybo. So it seems to me, too, that CodeNewbie's lynx has no links. A further 4-letter word can be transformed only by splitting: elhi.

There are also the following 2-word islands which contain words of no more than 4 letters: zuz-zzz; ebb-ebbs; amok-amoks; iglu-iglus; kufi-kufis; onyx-oryx. There are also word pairs which would have been 2-word islands except for the splitting option: exam-exams; isba-isbas; upby-upbye; weka-wekas.

Using the SOWPODS wordlist, the shortest isolani are 4 letters long: aesc enuf euoi mwah occy pfft yunx. A further 4-letter word can be transformed only by splitting: yebo.

There are also the following 2-word islands which contain words of no more than 4 letters: hwyl-hwyls; myxo-myxos; omov-omovs; vuln-vulns; waac-waacs. There is also a word pair which would have been a 2-word island except for the splitting option: exam-exams.

Some examples of SOWPODS neighbours to TWL isolani: asci-fasci-fasti; lynx-lyne and beginner 101's lynx-jynx; sybo-kybo-kobo-kobs. SOWPODS also has a link from elhi other than the split el hi: elchi.

Wikipedia's pages on TWL06 and SOWPODS contain links to the respective complete lists, in .txt form.

• Your suggestion of "ebb" is one letter shorter than the previously accepted lynx, so I've given you the tick. zuz-zzz also works, but I personally don't feel that zzz should count as a real word! Jun 22, 2016 at 15:44

A 4 letter word that I found to be a dead-end word ladder island

xenon vixen lynx

The plural is lynxes, so that isn't a possible move. ly is just a suffix, whereas lyn is an abbreviation which makes that invalid too. So splitting it is not useful. Trying for replacements gives us Lynn and Lynd but both are invalid as they are proper nouns.

• xenon -> tenon -> ten on -> tend on -> rend on -> read on -> dead on -> dead an -> dead and -> dead end. Hmm? Aug 19, 2015 at 18:43
• Aug 19, 2015 at 19:08
• vixen -> vimen => vim en Aug 19, 2015 at 19:08
• Ah, when I said "that doesn't count", I meant 'lynix' doesn't count as a contradictor. I think you've found a good one here. :D Aug 19, 2015 at 19:52
• sorry, but how about jynx at dictionary.reference.com/browse/jynx?s=t Aug 19, 2015 at 21:03

Taking a step back from the ambitious 4-letter words (though I'm certain there has to be something), I found this among five letters:

ZEBRA

1. Removals and splitting: I used dictionary.com directly and tried removing each letter and got no legal words. I also tried spliting at every possible joint and got no legal words.

2. Additions: Using this tool, I searched for words containing a letter added in any spot and got no legal words.

3. Replacements: Using this tool, I found only two words achieved by replacing a letter:

DEBRA and ZABRA

The first is of course a proper noun and the second doesn't appear on dictionary.com

4.But what about the trivial 'S'? According to dictionary.com, the plural does in fact have an s (I've heard it pluralized the same, like moose). But running that through the same gauntlet above, you get similar results (one less result in step 3 even)

I trust these tools are reliable, but if anyone finds something I missed, let me know

Okay, here's a 6-letter word, which I checked using this tool:

http://boulter.com/scrabble/

Sphinx and Sphynx

1. Couldn't find any 5-letter words using the same letters, so that removes deletion.
2. Inserting letters didn't create any new words that I could see (and the plural is -es, not -s, which helps with the trivial case)