Longest word in the English language?

pneumonoultramicroscopicsilicovolcanoconiosis is a word, it mean a lung condition that is caused by breathing in volcanic ash or dust for long periods of time, one of the longest words in the world is
ACETYL­SERYL­TYROSYL­SERYL­ISO­LEUCYL­THREONYL­SERYL­PROLYL­SERYL­GLUTAMINYL­PHENYL­ALANYL­VALYL­PHENYL­ALANYL­LEUCYL­SERYL­SERYL­VALYL­TRYPTOPHYL­ALANYL­ASPARTYL­PROLYL­ISOLEUCYL­GLUTAMYL­LEUCYL­LEUCYL­ASPARAGINYL­VALYL­CYSTEINYL­THREONYL­SERYL­SERYL­LEUCYL­GLYCYL­ASPARAGINYL­GLUTAMINYL­PHENYL­ALANYL­GLUTAMINYL­THREONYL­GLUTAMINYL­GLUTAMINYL­ALANYL­ARGINYL­THREONYL­THREONYL­GLUTAMINYL­VALYL­GLUTAMINYL­GLUTAMINYL­PHENYL­ALANYL­SERYL­GLUTAMINYL­VALYL­TRYPTOPHYL­LYSYL­PROLYL­PHENYL­ALANYL­PROLYL­GLUTAMINYL­SERYL­THREONYL­VALYL­ARGINYL­PHENYL­ALANYL­PROLYL­GLYCYL­ASPARTYL­VALYL­TYROSYL­LYSYL­VALYL­TYROSYL­ARGINYL­TYROSYL­ASPARAGINYL­ALANYL­VALYL­LEUCYL­ASPARTYL­PROLYL­LEUCYL­ISOLEUCYL­THREONYL­ALANYL­LEUCYL­LEUCYL­GLYCYL­THREONYL­PHENYL­ALANYL­ASPARTYL­THREONYL­ARGINYL­ASPARAGINYL­ARGINYL­ISOLEUCYL­ISOLEUCYL­GLUTAMYL­VALYL­GLUTAMYL­ASPARAGINYL­GLUTAMINYL­GLUTAMINYL­SERYL­PROLYL­THREONYL­THREONYL­ALANYL­GLUTAMYL­THREONYL­LEUCYL­ASPARTYL­ALANYL­THREONYL­ARGINYL­ARGINYL­VALYL­ASPARTYL­ASPARTYL­ALANYL­THREONYL­VALYL­ALANYL­ISOLEUCYL­ARGINYL­SERYL­ALANYL­ASPARAGINYL­ISOLEUCYL­ASPARAGINYL­LEUCYL­VALYL­ASPARAGINYL­GLUTAMYL­LEUCYL­VALYL­ARGINYL­GLYCYL­THREONYL­GLYCYL­LEUCYL­TYROSYL­ASPARAGINYL­GLUTAMINYL­ASPARAGINYL­THREONYL­PHENYL­ALANYL­GLUTAMYL­SERYL­METHIONYL­SERYL­GLYCYL­LEUCYL­VALYL­TRYPTOPHYL­THREONYL­SERYL­ALANYL­PROLYL­ALANYL­SERINE

Photo of floccinauccinihilipilification

German doesn't count, because you can string words together to make longer ones, and it still makes sense - 9,999 in German is neinthausandneinhundertneinundneinzig - all one word (as opposed to the english which is nine-thousand-nine-hundred-and-ninety-nine - all hyphenated). The longest German word I know is (without the accents that I can't type): Das Donaudampfgesselschaftskapitanmutzensilbersteinlein, meanind the little silver star on the hat of the captain of the Danube shipping society. But it doesn't count because you could add more words inside, to mean the little six-pointed ater, or the the eighty-ninth captain, and so on

Those aren't thee longest words! What about pneumonoultramicroscopicsilicovolcanoconiosis?
If you want to find this word you need to look in an unibridged dictionry page 1491.

acetylseryltyrosylserylisoleucylthreonylserylprolylserylglutaminylphenylalanylvalylphenylalany
lleucylserylserylvalyltryptophylalanylaspartylprolylisoleucylglutamylleucylleucylasparaginylval
ylcysteinylthreonylserylserylleucylglycylasparaginylglutaminylphenylalanylglutaminylthreonylg
lutaminylglutaminylalanylarginylthreonylthreonylglutaminylvalylglutaminylglutaminylphenylala
nylserylglutaminylvalyltryptophyllysylprolylphenylalanylprolylglutaminylserylthreonylvalylargi
nylphenylalanylprolylglycylaspartylvalyltyrosyllysylvalyltyrosylarginyltyrosylasparaginylalanyl
valylleucylaspartylprolylleucylisoleucylthreonylalanylleucylleucylglycylthreonylphenylalanylasp
artylthreonylarginylasparaginylarginylisoleucylisoleucylglutamylvalylglutamylasparaginylgluta
minylglutaminylserylprolylthreonylthreonylalanylglutamylthreonylleucylaspartylalanylthreonyl
arginylarginylvalylaspartylaspartylalanylthreonylvalylalanylisoleucylarginylserylalanylasparagi
nylisoleucylasparaginylleucylvalylasparaginylglutamylleucylvalylarginylglycylthreonylglycylleu
cyltyrosylasparaginylglutaminylasparaginylthreonylphenylalanylglutamylserylmethionylserylgl
ycylleucylvalyltryptophylthreonylserylalanylprolylalanylserine or is it

methionylglutaminylarginyltyrosylglutamylserylleucylphenylalanylalanylglutaminylleucyllysylgl
utamylarginyllysylglutamylglycylalanylphenylalanylvalylprolylphenylalanylvalylthreonylleucylgl
ycylaspartylprolylglycylisoleucylglutamylglutaminylserylleucyllysylisoleucylaspartylthreonylleu
cylisoleucylglutamylalanylglycylalanylaspartylalanylleucylglutamylleucylglycylisoleucylprolylph
enylalanylserylaspartylprolylleucylalanylaspartylglycylprolylthreonylisoleucylglutaminylaspara
ginylalanylthreonylleucylarginylalanylphenylalanylalanylalanylglycylvalylthreonylprolylalanylgl
utaminylcysteinylphenylalanylglutamylmethionylleucylalanylleucylisoleucylarginylglutaminyllys
ylhistidylprolylthreonylisoleucylprolylisoleucylglycylleucylleucylmethionyltyrosylalanylasparagi
nylleucylvalylphenylalanylasparaginyllysylglycylisoleucylaspartylglutamylphenylalanyltyrosylal
anylglutaminylcysteinylglutamyllysylvalylglycylvalylaspartylserylvalylleucylvalylalanylaspartyl
valylprolylvalylglutaminylglutamylserylalanylprolylphenylalanylarginylglutaminylalanylalanylle
ucylarginylhistidylasparaginylvalylalanylprolylisoleucylphenylalanylisoleucylcysteinylprolylprol
ylaspartylalanylaspartylaspartylaspartylleucylleucylarginylglutaminylisoleucylalanylseryltyrosyl
glycylarginylglycyltyrosylthreonyltyrosylleucylleucylserylarginylalanylglycylvalylthreonylglycyl
alanylglutamylasparaginylarginylalanylalanylleucylprolylleucylasparaginylhistidylleucylvalylala
nyllysylleucyllysylglutamyltyrosylasparaginylalanylalanylprolylprolylleucylglutaminylglycylphe
nylalanylglycylisoleucylserylalanylprolylaspartylglutaminylvalyllysylalanylalanylisoleucylaspart
ylalanylglycylalanylalanylglycylalanylisoleucylserylglycylserylalanylisoleucylvalyllysylisoleucyli
soleucylglutamylglutaminylhistidylasparaginylisoleucylglutamylprolylglutamyllysylmethionylleu
cylalanylalanylleucyllysylvalylphenylalanylvalylglutaminylprolylmethionyllysylalanylalanylthreo
nylarginylserine

or

Propseudocontraneoantidisestablishmentarianalistically

and the railway station

Gorsafawddacha'idraigodanheddogleddollônpenrhynareurdraethceredigion

Shakespeare's longest word

honorificabilitudinitatibus

and finally:

207,000+ letter word cited by the Guinness Book of Records which allegedly represents the name for human mitochondrial DNA. (cannot find it in full)

Ps: I'll let you count the number of letters in the first few words