eggcorn

noun

Etymology: Suggested by British-American linguist Geoffrey K. Pullum following a discussion on the Language Log website on September 23, 2003, by American linguist Mark Liberman, about a woman who had long believed the word acorn to be egg corn.

1. A word or phrase that sounds like and is mistakenly used in a seemingly logical or plausible way for another word or phrase either on its own or as part of a set expression

   “update (9/30/2003): Geoff Pullum suggests that if no suitable term already exists for cases like this, we should call them "egg corns", in the metonymic tradition of "mondegreen", since the eponymous solution of "malapropism" and "spoonerism" is not appropriate.”

   “The Language Loggers have argued that it's useful to distinguish eggcorns from classic malapropisms (e.g., "allegory" for "alligator", "oracular" for "vernacular", "fortuitous" for "fortunate"), in which a word is replaced by one with a vague similarity of sound. An eggcorn relies on a substitution that is phonologically very similar (even homophonous), and the result is one that is semantically justifiable (even if the justification is far-fetched).”