A.Word.A.Day with Anu Garg :eggcorn
noun: An erroneous alteration of a word or phrase, by replacing an original word with a similar sounding word, such that the new word or phrase also makes a kind of sense.
For example: "ex-patriot" instead of "expatriate" and "mating name" instead of "maiden name".
ETYMOLOGY: Coined by linguist Geoffrey Pullum (b. 1945) in 2003. From the substitution of the word acorn with eggcorn. Earliest documented use as a name for this phenomenon is from 2003, though the term eggcorn has been found going back as far as 1844, as "egg corn bread" for "acorn bread".

G to A

e.g. acorn - a definition of eggcorn.