I love long words, but I don’t set out to use them in real life. For some reason, I find 20-letter words more satisfying than 19- or 21-letter words, or any other length. I started collecting them but the internet has made it less fun than randomly encountering them (search and I’m sure you’ll find). Recently I randomly encountered the word fundamentalistically.
English words can gain prefixes and/or suffixes, but the latter are more likely than the former. Fundamentalistically is fundament (N) + al (adj) + ist (N) + ic (adj) + al (adj) + ly (adv). It is questionable whether fundamentalistical is a ‘real word’ and, if so, means anything different from fundamentalistic. Google shows 54 results for fundamentalistical, mostly on websites which I wouldn’t willingly read. Word for Mac doesn’t like fundamentalistically, autocorrecting it to fundamentalistic ally, then red-underlining it when I change it back, or fundamentalistical.
Antidisestablishmentarianism is often given as an example of a very long word (which it is) or the longest word in English (which it isn’t). We can easily follow a different chain of suffixes and create antidisestablishmentarianistically. Note that most suffixes change nouns into verbs and vice versa, or into adjectives and vice versa, but our chain ends with the adverbial suffix –ly, which doesn’t seem to allow any further suffix (except maybe –ish). On the other hand, it is very hard to add more than two prefixes, except maybe pseudo-antidisestablishmentarianistically (and that would almost certainly need a hyphen).
Searching my hard drive easily found a document with 15 or 16 20-letter words, in a draft for a website of which I was an active reader and commenter. They are (I suspect in order of commonness): tetrahydrocannabinol, *radiopharmaceuticals, crystallographically, counterrevolutionary, *semiautobiographical, electroencephalogram, compartmentali(z/s)ation, electrocardiographic, *noninstitutionali(z/s)ed, uncharacteristically, institutionalisation, **hypercholesterolemia (also spelled **hypercholesterolaemia – 21 letters), electrophysiological, **immunohistochemistry and internationali(z/s)ation. (* = not recognised by Pages for Mac or WordPress, but accepted with a hyphen after the first morpheme. ** = not recognised even with a hyphen.)
I also noted that mulitmillionairesses didn’t exist (until now). In fact multimillionairess doesn’t seem to exist, either. It’s not that women with a net worth of multiple millions of dollars don’t exist; it’s just that we don’t refer to them that way. They are simply multimillionaires (which is not by itself a gendered term; it’s just that the first multimillionaires were all men, and still most are) or even millionaires. (I am a multithousandaire, but we probably don’t need that word. If Sydney house prices keep rising, my wife and I may be a collective millionaire some time, at least in bricks, even for a modest townhouse (or maybe not – most practical calculations of net worth exclude the principal place of residence), but probably not a millionaire each.) Note that some multimillionairesses may be actresses but probably aren’t authoresses.
I also just made up sesquipedalianistics (the study of very long words).
(PS While I was adding tags for this post, I realised that probably all of these words are Latin or Greek in origin. It may be possible to create a very long Germanic words. German does.)