The actual longest word (according to The Top 10 of Everthing book) is:
Ornicopytheobibliopsychocrystarroscioaerogenethliometeoroaustrohieroanthrop
oichthyopyrosiderochpnomyoalectryoophiobotanopegohydrorhabdocrithoaleuroalp
hitohalomolybdoclerobeloaxinocoscinodactyliogeolithopessopsephocatoptroteph
raoneirochiroonychodactyloarithstichooxogeloscogastrogyrocerobletonooenosca
pulinaniac
letter count: 310.
The description is too long to write. :/