Webster's Third New International Dictionary

Webster's Third New International Dictionary of the English Language, Unabridged (commonly known as Webster's Third, or W3) was published in September 1961. It was edited by Philip Babcock Gove and a team of lexicographers who spent 757 editor-years and $3.5 million. The most recent printing has 2,816 pages, and as of 2005, it contained more than 476,000 vocabulary entries (including more than 100,000 new entries and as many new senses for entries carried over from previous editions), 500,000 definitions, 140,000 etymologies, 200,000 verbal illustrations, 350,000 example sentences, 3,000 pictorial illustrations and an 18,000-word Addenda section.

Webster's Third New International Dictionary
Preceded byWebster’s New International Dictionary (second edition, 1934) 

The final definition, Zyzzogeton, was written on October 17, 1960; the final etymology was recorded on October 26; and the final pronunciation was transcribed on November 9. The final copy went to the typesetters, R. R. Donnelley, on December 2. The book was printed by the Riverside Press in Cambridge, Massachusetts. The first edition had 2,726 pages (measuring 9 in or 230 mm wide by 13 in or 330 mm tall by 3 in or 76 mm thick), weighed 13+12 lb (6.1 kg), and originally sold for $47.50 ($411 in 2020 dollars[1]). The changes were the most radical in the history of the Unabridged.

Although it was an unprecedented masterwork of scholarship, it was met with considerable criticism for its descriptive (rather than prescriptive) approach.[2] It told how the language was used, not how it ought to be used.[3]