You searched for: “sesquipedality”
sesquipedality (s) (noun), sesquipedalities (pl)
The practice of using abnormally long words: "The famous orators, who were famous for their sesquipedalties, engaged in verbal debates as they tried to use longer words than their opponents."
This entry is located in the following units: -ity (page 16) ped-, pedi-, -pedal, -ped, -pede, -pedia (page 10) sesqui- (page 2)