longest word (thing)

Longest Word in the English Language Dictionary

At 45 letters Pneumonoultramicroscopicsilicovolcanoconiosis is the longest non-scientific/place-name word in any English language dictionary.

The word appears in the 1936 Supplement to OED1, the OED2, the addendum to W2 (spelled -koniosis), W3 (spelled -coniosis), RHUD2, and Chambers.

The OED2 has:

• pneumonoultramicroscopicsilicovolcanoconiosis (-koniosis), a factitious word alleged to mean 'a lung disease caused by the inhalation of very fine silica dust' but occurring chiefly as an instance of a very long word.
• 1936 F. Scully Bedside Manna 87 *Pneumonoultramicroscopicsilicovolcanakoniosis sic, a disease caused by ultra-microscopic particles of sandy volcanic dust, might give even him laryngitis.
• 1966 Word Study Oct. 7/2 The resources of Greek have enriched the modern world as well as the ancient one. Perhaps this is most dramatically illustrated by the longest and most fantastic word now in an English dictionary (the Merriam-Webster’s great Unabridged) which is forty-five letters in length: pneumonoultramicroscopicsilicovolcanoconiosis,..meaning 'a disease of the lungs caused by extremely small particles of ash and dust'.
• 1973 R. Megarry Second Miscellany-at-Law 160 It has been said that 'floccinaucinihilipilification' is the longest word in the English language... The word’s proud title must yield to some technical terms, such as pneumonoultramicroscopicsilicovolcanokoniosis.

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