The longest English word and other curious words

The longest english word: The question of determining the longest english word inevitably boils down to defining what is acceptable as a word, since prefixes/suffixes can be adjoined to words to make longer words and because medical/chemical terms can get arbitrarily long. Further, most contenders for the honor of being the longest word are likely to be very rare in actual usage - so rare, in fact that they could be considered nonce words. The most common candidates for the crown, in my opinion, are

The first is the only one of the three that was not specifically constructed for the purpose of being a very long word. It means opposition to the separation of church and state. The second, meaning the estimation of something as worthless, is the longest non-technical word in the OED. The latter, supposedly a lung disease, appears to be a semi-serious concoction. More information on this question can be found here.

Lexically interesting words. Various types of lexically interesting words are listed below. These aren't official in any sense, just the results of my grepping the Moby's word list one bored afternoon.

• Longest word without a vowel: symphysy. Runners-up: nymphly, rhythms, gypsyfy, gypsyry. Excluding 'y': crwths.
• Longest word with at most 1 vowel: glycyphyllin, psychorhythm.
• Word with most vowels: counterrevolutionaries (among others).
• Word with most consecutive vowels (5): cooeeing, miaoued, miaouing, queueing. (Euouae, consisting of nothing but 6 vowels, is of doubtful legitimacy.)
• Smallest word with all 5 vowels: eulogia, miaoued, sequoia.
• Longest word with only 3 distinct alphabets: seeresses.
• Longest word with only 4 distinct alphabets: senselessness.
• Longest word with no repeated letter: dermatoglyphics.
• Longest word with letters in alphabetical order: aegilops.
• Longest word with letters in reverse alphabetical order: trollied.
• Longest word that can be typed with the right hand alone (on a qwerty keyboard): phyllophyllin.
• Longest word that can be typed with the left hand alone (on a qwerty keyboard): devertebrated.
• Longest word that can be typed using the top row (of a qwerty keyboard): rupturewort. Runners-up: peppertree, pepperwort, perpetuity, proprietor, repertoire, tetterwort, typewriter.
• Interesting words with the substring 'uu': continuum, fatuus, menstruum, residiuum, vacuum.
• Word with the maximum number of distinct alphabets (16): blepharoconjunctivitis, formaldehydesulphoxylic, pneumoventriculography, pseudolamellibranchiate, superacknowledgment.
• Word with most a's (6): astragalocalcaneal, calcaneoastragalar, taramasalata.
• Word with most e's (7): electrotelethermometer.
• Word with most i's (6): impossibilification, indistinguishability, indivisibility, minimifidianism, pericardiomediastinitis.
• Word with most o's (6): choledochoduodenostomy, duodenocholedochotomy, monogonoporous, odontonosology, proctocolonoscopy, pseudomonocotyledonous, zoologicoarchaeologist.
• Word with most u's (5): untumultous.
• Words with four consecutive letters of the alphabet appearing consecutively:
  • mnop: cremnophobia, gymnopaedic, gymnoplast, limnophile, somnopathy (and a few others).
  • rstu: overstudy, overstuff, understudy, afterstudy, overstudious, superstuff, understuff (and a few others).
• Words with four consecutive letters of the alphabet appearing consecutively in reverse order:
  • ponm: tamponment, weaponmaker.
• Words with 3 consecutive s's: bossship, headmistressship, patronessship.
• The last word: zyzzyva.

See also: A Collection of Word Oddities and Trivia - A large collection of all kinds of curious words.