
The longest phrase within the English language is pneumonoultramicroscopicsilicovolcanoconiosis, a lung illness brought about through the inhalation of very effective silica mud, generally present in volcanoes.
The phrase used to be first coined through American doctor and creator Everett M. Smith in 1935. He created the phrase from the Greek roots pneumono (lung), extremely (very), microscopic (small), silico (silicon), volcano (volcano), and -osis (situation). The phrase is 45 letters lengthy and is pronounced as noo-moh-no-ul-tra-mih-kroh-skoh-pih-ko-sih-lih-koh-voh-lka-noh-koh-nee-oh-sis.