An eggcorn is an error in usage where the word is altered to a more familiar form that sounds nearly the same; acorn becomes eggcorn or in high dudgeon is changed to in high dungeon. An eggcorn differs from a folk etymology in that the former is an error by a single individual while the latter is a usage adopted by a wider group. An eggcorn could develop into a folk etymology as it gets wider use, as may be happening with hone in on in place of home in on. Eggcorns are similar to mondegreens.
The term eggcorn was coined in September 2003 when linguist Mark Liberman posted to Language Log asking for a name for this phenomenon. He used eggcorn/acorn as an example. Fellow linguist Geoff Pullum responded with the suggestion that they be called eggcorns.
(Source: Language Log)
Copyright 1997-2013, by David Wilton