eggcorn

:  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 Eggcorns … are a particular type of language error. Though incorrect, eggcorns are often more satisfying or poetic than the correct word or expression. If you didn't know how to spell the word “acorn,” then “eggcorn” is a logical and satisfying alternative. A layman is certainly lame compared with an expert, and chickens are as likely to roast as roost. What distinguishes such a mistake from an ordinary malaprop—a word that is unintentionally misused through confusion with one that sounds similar—is the creativity and logic behind them. — New Scientist, 26 Aug. 2006 Once described as a “slip of the ear,” an eggcorn is the written expression of a plausible mishearing of a standard term. “For all intents and purposes,” for example, is a set phrase—inherently redundant, perhaps, but it's the idiom. It gets misheard, though, as “for all intensive purposes,” and sometimes appears that way in print. That's an eggcorn. — Ruth Walker, Christian Science Monitor, 6 June 2011 ◆The word eggcorn in this sense was coined by the linguist Geoffrey Pullum.