Longest word in English without repeated letter [closed]

Question

What is the longest word you can come up with that is a real English word that doesn't use any individual letter more than once?

Answer 1

The usual answer (longer than nohat's discoveries, probably because the CMU dictionary doesn't contain it, but certainly a valid English word) is "UNCOPYRIGHTABLE", 15 letters.

Dermatology journals also contain the word SUBDERMATOGLYPHIC, 17 letters.

Answer 2

I wrote a quick little Perl script to scan through the CMU Pronouncing Dictionary:

#!/usr/local/bin/perl
use warnings;
use strict;
use Data::Dumper;
my @size;
while (<>) {
    my ($word) = split /  /, $_;
    next unless $word =~ m/^[A-Z]+$/;
    my @letters = split //, $word;
    my %count;
    $count{$_}++ foreach @letters;
    next if grep { $_ > 1 } values %count;
    push @{$size[length($word)]}, $word;
}
print Dumper(pop @size);

Here is the output:

$VAR1 = [
          'COPYRIGHTABLE',
          'UNPREDICTABLY',
          'WOLFENSCHMIDT'
        ];

The third is debatably an English word—it’s a name—but they are all 13 letters long.

Answer 3

You can take a look at wikipedia: Isogram

Answer 4

A popular trivia quiz question along these lines is 'what is the longest place name in Britain that doesn't repeat any letters?' Nobody has yet found one longer than 'Bricklehampton'.

Answer 5

A quick Google search revealed a post with the following list:

• 15,"dermatoglyphics"
• 15,"uncopyrightable"
• 14,"troublemakings"
• 14,"dermatoglyphic"
• 14,"ambidextrously"
• 13,"documentarily"
• 13,"consumptively"
• 13,"copyrightable"
• 13,"endolymphatic"
• 13,"flowchartings"
• 13,"hydromagnetic"
• 13,"lycanthropies"
• 13,"troublemaking"
• 13,"unpredictably"
• 13,"unproblematic"
• 13,"subordinately"
• 13,"metalworkings"
• 13,"multibranched"

Answer 6

In the dictionaries which come with FreeBSD I find:

14: ambidextrously
14: benzhydroxamic
15: dermatoglyphics

Answer 7

From Fun with Words:

The longest words with no repeated letters are dermatoglyphics, misconjugatedly and uncopyrightables.

Answer 8

How about:

pneumonoultramicroscopicsilicovolcanoconiosis

(And I'm not just making that up!) … I learned it as a kid, in the hopes that I could win the national spelling bee with it. ;)