sesquipedalian

noun

1. A long word.

   ““The fine old fellow,” as a Northern contemporary of ours patronizingly calls him, certainly rolled out his sesquipedalians with a majesty previously unknown, and gave a fine organ-like swell to his full-blow periods;”

   “Fleet-streetese, the so-called English written to sell by the Fleet-streeter (q.v.), or baser sort of journalist: a mixture of sesquipedalians and slang, of phrases worn threadbare and phrases sprung from the kennel;”

   “‘Sometimes we converse in ballad-rhymes, sometimes in Johnsonian sesquipedalians; at tea we condescend to riddles and charades.’”

2. A person who uses long words.

   “Word-watchers, verbivores, and sesquipedalians love a challenge.”

   “‘What sort of writer is the English professor looking for?’ / ‘He wants a sesquipedalian, of course.’”

   “Don’t be a sesquipedalian! / Yes, you guessed right. A sesquipedalian is a person who enjoys long words.”

adj

1. Long; polysyllabic.

   “The most common use of "antidisestablishmentarianism" is as an example of a sesquipedalian word.”

   “He would use the simplest, plainest language, he said to himself over and over again; but it is not always easy to use simple, plain language,—by no means so easy as to mount on stilts, and to march along with sesquipedalian words, with pathos, spasms, and notes of interjection.”

   “Happy word hunting! You might bag a sesquipedalian trophy! (Look it up in the dictionary).”

2. Pertaining to or given to the use of overly long words.

   “Our dinner guest was so sesquipedalian that no one could understand what he said.”

   “[I]ts main character, Henry (Mr. [Ewan] McGregor), is a successful, intellectual dramatist who seems quite capable of churning out fizzy, challenging works about brilliant but ambivalent revolutionaries, philosophers, etc. […] But this cleverer-than-thou creature gets his comeuppance in "The Real Thing," showing that a very human heart – just like those possessed by the less sesquipedalian – beats beneath his fancy words.”