Sesquipedalian
Etymology
From Latin "sesquipedalis," literally "a foot and a half long" (sesqui- "one and a half" plus "pes/pedis," foot). The Roman poet Horace used "sesquipedalia verba" — "words a foot and a half long" — in his Ars Poetica to mock bombastic diction.
adjective · /ses-kwih-puh-DAY-lee-un/
Given to using long words; or, of a word, very long and cumbersome.
What it names
Enacts its own meaning — the ideal label for prose or a speaker overfond of ten-dollar words when a plain one would do.
Example
His sesquipedalian emails, dense with "heretofore" and "notwithstanding," took three readings to decode.
Related idea
Broader than sesquipedalian is grandiloquent, which condemns a whole lofty, pompous style; sesquipedalian points specifically at the length of the words.
See also