This node is all about made-up words (also called ghost words) that made it into otherwise well-respected dictionaries, and errors in those dictionaries.

(Now split into separate nodes not so much to increase my everything experience as to avoid making this a really, really long node.)

The most famous of these fake words has to be pneumonoultramicroscopicsilicovolcanoconiosis, and the most famous error has to be dord, both from Merriam Webster's New International Dictionary, Second Edition (NI2). Also from NI2: phantomnation, raftman, rei.

From Merriam-Webster's Third New International Dictionary: balge yellow.

This great dictionary is now available on CD-ROM! See also Errors in the NI3 on CD-ROM.

From Samuel Johnson's (1755) Dictionary of the English Language: pastern, foupe.

From the first edition of the Oxford English Dictionary: floccinaucinihilipilification

As far as some of these being put in as Easter eggs, I have omitted those (or the ones that are thought to have been added for that reason). But in the 19th century, this was in fact common. One particular phony that appeared in a dictionary, abacot, was a misspelling of a word copied from another dictionary, which was a misspelling of a word copied from yet another dictionary, which was an intentional misspelling of some obscure Scottish word inserted to catch such copying. One only wonders if all the other misspellings were also intentional.