In the game there is a convention, established in 1992, that we never play a word that has been played before, no matter how long ago. Here you can find all of the words dealt in Dixonary since Round 1, in which the word was keckle, together with the round number, and the name of the player who selected the word and dealt the round. An asterisk in the column Word abandoned or withdrawn indicates that the word was announced, but was withdrawn and a substitute played in its place, or (very occasionally) that the round could not be completed. In this case the players declare a redeal and start the round afresh, under the same round number as the uncompleted round.
This list has been maintained by various players over the years: Russ Heimerson (1945–2010), John Barrs, and currently Dan Widdis and Paul Keating.
Below is a link to a Google Sheet with the latest list. It is publicly viewable. Some things you can do with read-only permission include:
(File menu) Download a copy to your local machine to leverage sorting/searching features
(Data menu) Filter Views -> Sort Columns
(Ctrl-F) Search the sheet for text
To leverage online editing features, log in with a Google account. If that account is a member of the Dixonary Google Group, you don't need to request permission for this, because you already have it.
The text files record used words in a format that was devised in 1990 for the Files section of the original CompuServe forum. The format was fixed, because at the time there were dealer support programs that were written to expect exactly that format. That no longer matters, and the maintainers opted to make a Google Sheet the primary format. The text files are occasionally updated out of sheer boredom, but cannot be relied upon. So please do not use them as an offline oracle. If you feel you must have a local file, create your own up-to-date one: open the spreadsheet at the Word List tab, then
From a desktop: From the menu, File | Download, and choose your preferred format.
From a mobile phone: Tap ⋮ at top right, then Share & export | Save as, and choose your preferred format.
If you look for copies of these files in the Google Group, you will find them as static copies attached to posts: that will turn up about a dozen versions, some more than a decade out of date.