The nucleus of this collection was a dictionary for playing a game called Jotto, compiled by Michael Beeler prior to 1971  and extended shortly afterward to a list of 6627 words corresponding to the contents of the Webster's 7th New Collegiate Dictionary. Beeler estimated that 16,000 words would have been present if he had used an unabridged dictionary. But the 6627 five-letter words in Webster's Collegiate already included plenty of esoterica, so the author pared Beeler's list down by removing whatever he could not remember seeing previously.Knuth also mentions that he did not do any "censorship" on this list of words. Neither have I. So it is possible that this word list may contain words that some of you may find inappropriate. However, note that for this project, you don't have to read the words, your program does. I hope that you will all view this word list in the broader context of the project as simply an interesting data set that provides a way to generate an interesting graph. Here is the word list: words.dat.
Additional words were added to the culled file during the next 20 years whenever the author came across a bona fide five-letter word that was not present.