Nouns

(n)sesquipedalian, sesquipedaliaa very long word (a foot and a half long)

Adjectives

(s)sesquipedaliangiven to the overuse of long words“sesquipedalian orators”, “this sesquipedalian way of saying one has no money”
(s)polysyllabic, sesquipedalian(of words) long and ponderous; having many syllables“sesquipedalian technical terms”