Rules of the contest:
Say the biggest word you know,
Define it,
Win the contest! No prize. Just for the lulz.
Supercalafragilistic does not count, you must define it.
My entry- Hippopotomonostrosusquipadaliaphobia: The fear of long words. Beat that fools!

1907014 okay 0u0
Methionylthreonylthreonylglutaminylarginyl ... isoleucine

1907038
Oh you little bitch. You didn't even put the whole thing! And where's the definition?

1907068 heres some of it===
Methionylalanylthreonylserylarginylglycylalanylserylarginylcysteinylproly-
larginylaspartylisoleucylalanylasparaginylvalylmethionylglutaminylarginyl-
leucylglutaminylaspartylglutamylglutaminylglutamylisoleucylvalylglutaminy-
llysylarginylthreonylphenylalanylthreonyllysyltryptophylisoleucylasparagi-
nylserylhistidylleucylalanyllysylarginyllysylprolylprolylmethionylvalylva-
lylaspartylaspartylleucylphenylalanylglutamylaspartylmethionyllysylaspart-
ylglycylvalyllysylleucylleucylalanylleucylleucylglutamylvalylleucylserylg-
lycylglutaminyllysylleucylprolylcysteinylglutamylglutaminylglycylarginyla-
rginylmethionyllysylarginylisoleucylhistidylalanylvalylalanylasparaginyli-
soleucylglycylthreonylalanylleucyllysylphenylalanylleucylglutamylglycylar-
ginyllysylisoleucyllysylleucylvalylasparaginylisoleucylasparaginylserylth-
reonylaspartylisoleucylalanylaspartylglycylarginylprolylserylisoleucylval-
ylleucylglycylleucylmethionyltryptophylthreonylisoleucylisoleucylleucylty-
rosylphenylalanylglutaminylisoleucylglutamylglutamylleucylthreonylserylas-
paraginylleucylprolylglutaminylleucylglutaminylserylleucylserylserylseryl-
alanylserylserylvalylaspartylserylisoleucylvalylserylserylglutamylthreony-
lprolylserylprolylprolylseryllysylarginyllysylvalylthreonylthreonyllysyli-
soleucylglutaminylglycylasparaginylalanyllysyllysylalanylleucylleucyllysy-
ltryptophylvalylglutaminyltyrosylthreonylalanylglycyllysylglutaminylthreo-
nylglycylisoleucylglutamylvalyllysylaspartylphenylalanylglycyllysylserylt-
ryptophylarginylserylglycylvalylalanylphenylalanylhistidylserylvalylisole-
ucylhistidylalanylisoleucylarginylprolylglutamylleucylvalylaspartylleucyl-
glutamylthreonylvalyllysylglycylarginylserylasparaginylarginylglutamylasp-
araginylleucylglutamylaspartylalanylphenylalanylthreonylisoleucylalanylgl-
utamylthreonylglutamylleucylglycylisoleucylprolylarginylleucylleucylaspar-
tylprolylglutamylaspartylvalylaspartylvalylaspartyllysylprolylaspartylglu-
tamyllysylserylisoleucylmethionylthreonyltyrosylvalylalanylglutaminylphen-
ylalanylleucyllysylhistidyltyrosylprolylaspartylisoleucylhistidylasparagi-
nylalanylserylthreony....
Definition= the chemical name for titin, the largest protein ever discovered.
((had more than 50,000 characters...wouldn't show...DAMN))

1907111
I tried to post as well. Damn character maximum.

1907014

floccinaucinihilipilification

It means you underestimate the importance of things and I used it in my story:

Linc

That is all. Equestria is ours.

1907124 \_(0w0)_/
Ya can't do shit about it though.

Supercalafragilisticexpialadoucous WHAT DOES THE FOX SAY!

1907124
Fuck,I just read the top

Pneumonoultramicroscopicsilicovolcanoconiosis- "An obscure term ostensibly referring to a lung disease caused by silica dust, sometimes cited as one of the longest words in the English Language."

1907111 And then the game was over ...
That is one extremely long word.
~N

1908465 there's even more to it.
It has 186, 5 something or other letters in there.

1908477 I know, I went to its Wikipedia page.
~N

1908515 it's really fucking long

1907014
Damn it... I was going to say that...