“In linguistics, an eggcorn is an idiosyncratic substitution of a word or phrase for a word or words that sound similar or identical in the speaker's dialect. The new phrase introduces a meaning that is different from the original, but plausible in the same context, such as "old-timers' disease" for "Alzheimer's disease". This is as opposed to a malapropism, where the substitution creates a nonsensical phrase. Classical malapropisms generally derive their comic effect from the fault of the user, while eggcorns are errors that exhibit creativity or logic. Eggcorns often involve replacing an unfamiliar, archaic, or obscure word with a more common or modern word ("baited breath" for "bated breath").
The term eggcorn was coined by professor of linguistics Geoffrey Pullum in September 2003, in response to an article by Mark Liberman on the website Language Log, a blog for linguists. Liberman discussed the case of a woman who substitutes the phrase egg corn for the word acorn, arguing that the precise phenomenon lacked a name; Pullum suggested using "eggcorn" itself. The phenomenon is very similar to the form of wordplay known as the pun, except that, by definition, the speaker (or writer) intends the pun to have some effect on the recipient, whereas one who speaks or writes an eggcorn is unaware of the mistake.”