Eggcorn

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).

What is also required of eggcorns is phonetic closeness -- they should do better than "electrocution" for "elocution" or "allegory" for "alligator". This is something they have in common with mondegreens, but the similarity ends there. Mondegreens are errors of perception, not of production, and they are related to specific auditory material: […]

Far from being simple goofs, an eggcorn provides a glimpse into everyday thought processes. Eggcorns do not signify ignorance but rather the opposite, […]

An eggcorn is a term that is misunderstood and mangled, like ‘give up the goat’ or ‘hone in on’.

Our report of a relative who, as a child, thought the classic version of the Lord's Prayer began "Our father, a chart in heaven, Harold be thy name" stated that this type of mistake is known as an eggcorn. A number of readers have suggested that instances like this in which a whole phrase rather than just a word is misheard, should be called mondegreens rather than eggcorns.

[M]ost eggcorns remain individual idiosyncrasies […] But something like "pus jewel" (for "pustule") — which is an eggcorn […]