Misunderestimate? [/GWB]
[QUOTE=panamajack]
The word ‘apron’ used to be ‘napron’ until enough people who heard ‘a napron’ figured it should just be ‘an apron’.
Going the other way is ‘atomy’, which I’ve only ever seen in dictionaries - it means ‘a skeleton’. It’s a joke formation from the skeletons seen in anatomy classes (‘an atomy’)
[/QUOTE]
Another pair is “a newt” (originally “an ewt” and “an adder” (originally “a nadder”).
“Pea”, of course, is a back formation from “pease”.
Weren’t snafu and fubar originally joke military terms. They seem to have made it into civilian use quite readily.
[QUOTE=Aspidistra]
Lewis Carrol filled his poem “Jabberwocky” with many invented words such as ‘brillig’,‘slithy’, ‘gimble’ and so on, many of them probably “portmanteau words” (eg slithy=slither+slimy) which were a common fascination of Carrol’s.
…
[/QUOTE]
That’s ‘lithe’+‘slimy’, as explained in the book, and in the Wikipedia article.
Carroll and Dr. Seuss are two of my poetic heroes. 
[QUOTE=Malacandra]
Another pair is “a newt” (originally “an ewt” and “an adder” (originally “a nadder”).
“Pea”, of course, is a back formation from “pease”.
[/QUOTE]
And “cherry” is a back-formation from the French cherise. People hear the term ending in “s” and, applying general English language priciples, assume or designate the singular as the word minus the “s” A bunch of the item is “pease” therefore the singular item must be “a pea.” A bunch of the item is “cherise” so therfore the sigular item must be “a cherry.”
Isn’t that interesting?? Maybe only to me. 
But English language formation history stuff has always fascinated me. The mechanics of linguistics (voiced fricative, glottal stop): not so much.
Has jebus been mentioned?