Floccinaucinihilipilification

/ˌfläksēˌnäsēˌnihəlēˌpiləfəˈkāSHən/

Floccinaucinihilipilification (noun) is one of the longest words in English. Means, the act of describing or regarding something as unimportant, worthless, or of little value. 

It comes from a mashup of several Latin words (flocci, nauci, nihili, pili — all meaning "of little or no value") plus "-fication" (making/doing).

• His constant floccinaucinihilipilification of my ideas makes me not want to share them anymore.