# Longest substitution word pair
**URL:** https://boards.straightdope.com/t/longest-substitution-word-pair/784609
**Category:** Factual Questions
**Created:** [April 17, 2017, 7:24am UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609 "2017-04-17T07:24:01Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@dtilque](https://boards.straightdope.com/u/dtilque)
#### Post date: [April 17, 2017, 7:24am UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/1 "2017-04-17T07:24:01Z")
What’s the longest pair of words that differ by one letter? That is, you can get from one to the other by making a single letter substitution.
After thinking about this question, I figure the answer is probably some related words with -ism/-ist suffixes, for example antidisestablishmentarianis{m|t}. So let’s modify the question with the restriction that the two words aren’t related.
Further modification: What’s the longest pair when the substitution is between vowel and consonant and they are not related? (For the purpose of this question, the vowels are AEIOUY.) If we don’t have the related restriction, there’s hypercholesterolemi{a|c}, which is a pretty boring answer. I’m looking for something more like election/electron (which, despite their similarity, are not related at all, even if you go back to their Latin roots).
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### Author:  [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)
#### Post date: [April 17, 2017, 8:09am UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/2 "2017-04-17T08:09:59Z")
ichnographically - iconographically
I guess that’s kind of a cheat, since it’s just a short prefix that’s different, but I think it fits the criteria.
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### Author:  [@dtilque](https://boards.straightdope.com/u/dtilque)
#### Post date: [April 17, 2017, 8:47am UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/3 "2017-04-17T08:47:05Z")
That’s a good one. Those aren’t prefixes, but rather the words’ roots.
Just want to make some thing clear that may not have come across from my OP: I’m actually asking two questions. One for any substitution and one for vowel/consonant. Your answer may be the best for the v/c question.
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### Author:  [@septimus](https://boards.straightdope.com/u/septimus)
#### Post date: [April 17, 2017, 1:54pm UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/4 "2017-04-17T13:54:59Z")
It will be hard to best Dr, Strangelove’s vowel/consonant switch, but here are two pairs of long consonant/consonant switchers.
nationalistically rationalistically
phonographically photographically
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### Author:  [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)
#### Post date: [April 17, 2017, 3:08pm UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/5 "2017-04-17T15:08:10Z")
Some thoughts but no answers:
Clearly we get extended length from fancy prefixes and/or suffixes like -istically and -graphically.
It seems English is more generative in suffix land than in prefix land. e.g. -ically can be suffixed onto many other words that are themselves working as suffixes. ISTM prefixes don’t do that as much in English.
To get unrelated meaning we pretty well need to make the substitution in the root word. Unless someone can come up with two widely-unrelated suffixes that share all but one letter.
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### Author:  [@Quartz](https://boards.straightdope.com/u/Quartz)
#### Post date: [April 17, 2017, 3:40pm UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/6 "2017-04-17T15:40:47Z")
> [@Dr.Strangelove](#):
>
> ichnographically - iconographically
ichnographologicalisms - iconographologicalisms 🙂
BTW with _election_ you could have _ejection_ - throwing someone in versus throwing someone out. 🙂
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### Author:  [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)
#### Post date: [April 17, 2017, 4:18pm UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/7 "2017-04-17T16:18:35Z")
Don’t forget \*erection _which means something going up_.
# So we have motion in, out, and up all differing by one letter in the same position.
- e.g. A building you dirty-minded fiends. 🙂
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### Author:  [@dtilque](https://boards.straightdope.com/u/dtilque)
#### Post date: [April 17, 2017, 5:08pm UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/8 "2017-04-17T17:08:27Z")
> [@septimus](#):
>
> It will be hard to best Dr, Strangelove’s vowel/consonant switch, but here are two pairs of long consonant/consonant switchers.
>
> nationalistically rationalistically
> phonographically photographically
That first pair could be extended by prefixing both with hyper-. Won’t work for the second pair, at least not if you want to retain meaning.
> [@LSLGuy](#):
>
> Clearly we get extended length from fancy prefixes and/or suffixes like -istically and -graphically.
That’s a point. Let’s add a third question: What’s the longest where all the common affixes have been factored out? And a fourth question: the same with v/c substitution. (Note this requires both words to be able to have the affix removed and still have a valid word. If you can’t do that for both, leave it on.)
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### Author:  [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)
#### Post date: [April 17, 2017, 5:45pm UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/9 "2017-04-17T17:45:06Z")
> [@Dr.Strangelove](#):
>
> ichnographically…
What a great word! Thanks.
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### Author:  [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)
#### Post date: [April 18, 2017, 7:48am UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/10 "2017-04-18T07:48:02Z")
> [@Leo\_Bloom](#):
>
> What a great word! Thanks.
Glad you liked it. It was new to me, too.
This is a total cheat since they’re compound medical terms, and the most distant root is the same, but I can do better:
urethrovaginographically - ureterovaginographically
Urethrovaginography is a word that I totally didn’t make up. So is ureterovaginal. And while I can’t see that my particular words have ever been used before, I claim they’re legit.
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### Author:  [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)
#### Post date: [April 18, 2017, 11:03am UTC](https://boards.straightdope.com/t/longest-substitution-word-pair/784609/11 "2017-04-18T11:03:16Z")
Medicine is definitely the region of English that’s most fertile for this.
Lots of compound words already, fairly Germanic attitudes on compounding them further, and lots of lengthy Latin & Greek but little of the short sharp Anglo-Saxon stuff.
I just thought of something else which is at least as big a cheat as is medicine: Chemistry.
Compare (fake made up example) 2-4-5-cyclohexadimethyla **z** ide with 2-4-5-cyclohexadimethyla **m** ide. There’s -ite vs -ide, -amide vs -azide, alkane vs alkene vs alkyne, and umpteen others I’ve never heard of. Even better, the official rules [IUPAC nomenclature of organic chemistry - Wikipedia](https://en.wikipedia.org/wiki/IUPAC_nomenclature_of_organic_chemistry) encourage stringing all this polysyllabic gobbledygook together in thousand-syllable chains just as the chemists mix the actual goop together to make thousand-molecule polymers.
That’s so target-rich an environment that it almost has to be out of bounds for the thread’s purposes.