Hippopotomonstrosesquipedalian – of or pertaining to extremely long words .
Origin – An extension of sesquipedalian using a modified form of hippopotamus and Latin monstrum; the extensions almost certainly chosen with the intention of making the new construct autological. / Pronunciation: /ˌhɪpəˌpɒtəˌmɒnstɹəˌsɛskwɪpɪˈdeɪlɪən/ Adjective