This one comes right from Beakman’s World; allegedly the longest word in the English language (other than scientific terminology):
- floccinaucinihilipilification /ˌflɒksɪˌnɒsɪˌnɪhɪlɪˌpɪlɪfɪˈkeɪʃən/: act or habit of describing or regarding something as unimportant.