What word contains the most unique letters?

Question

I'm assuming there isn't a word that contains every letter in the alphabet, so which word contains the most?

Examples:

antidisestablishmentarianism - 12 [antidseblhmr]
psychotherapy - 12 [psychotherap]
handcraftsmanship - 13 [handcrftsmhip]

Answer 1

Among words in a certain word list I found:

(18, 'llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch')

It has ten words with 16, including:

(16, 'superacknowledgement')
(16, 'pseudolamellibranchiate')
(16, 'pneumoventriculography')
(16, 'phenylthiocarbamides')
(16, 'hippopotomonstrosesquipedaliophobia')
(16, 'formaldehydesulphoxylic')
(16, 'blepharoconjunctivitis')

There are several dozen with 15, including:

(15, 'undiscoverability')
(15, 'uncopyrightable')
(15, 'supermagnificently')
(15, 'supercalifragilisticexpialidocious')
(15, 'submetaphorically')
(15, 'spondylotherapeutics')
(15, 'semiautobiographical')
(15, 'pterygomandibular')
(15, 'pseudoromantically')
(15, 'overdiscriminatingly')
(15, 'neuropharmacologists')
(15, 'hyperconstitutionalism')
(15, 'honorificabilitudinities')
(15, 'gumpoldskirchner')
(15, 'formaldehydesulphoxylate')
(15, 'encephalomyocarditis')
(15, 'dermatoglyphics')

and several hundred with 14 (including a few 14-letter words like 'pseudomythical', 'hydropneumatic' and 'ambidextrously').

In case anyone cares, this was done with Python, something like:

F = open('words.list').readlines()
for i in range(len(F)):
    w = F[i].strip().lower()
    F[i] = (len(set(w)), w)
F = sorted(F, reverse=True)
for i in range(len(F)): print F[i]

A better word list (one that includes subdermatoglyphic, for instance!) may give longer words. And you didn't ask about two words, but just for reference: this says "Ralph Beaman proposes formaldehydesulphoxylic ventriloquizing as a two-word combination having 22 different letters which should be difficult to beat"; I haven't checked this.

Answer 2

Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch clocks in at 18 distinct characters, but arguably a near-infinite number of 25-character answers exist, since organic chemistry nomenclature allows one to build valid hypothetical compound names of essentially arbitrary length, and the full alphabet less only J appears on the periodic table (though this does require one to refer to rutherfordium by its old placeholder name unnilquadium or arrogate a placeholder name for a transuranic element with an atomic number ending in 4 that hasn't been named yet, so it may only get us to 24 characters).

Answer 3

Uncopyrightable is supposedly the longest word in the English language with no repeated letters, which makes it a logical starting point. That sets the bar at 15 unique letters.

Answer 4

Subdermatoglyphic = 17 (longest one seen so far).