Definitions for "back-formation"
Keywords:  affix, invented, verb, peddlar, peddle
a word invented (usually unwittingly by subtracting an affix) on the assumption that a familiar word derives from it, such as emote from emotion.
the process of inventing a back-formation{1}.
Word formation based on a mistaken morphological analysis. Usually this means dropping a part of the word when it is incorrectly thought to be an affix. In the case of "duh" and "Doh!" it has been done with a change in the vowel and other phonological refinements.