refers to the creation of a new word on the mistaken assumption that an existing word derives from it. Commonly, this involves the elimination of an affix or inflection, as in the creation of the verb enthuse from enthusiasm. The term is also applied to a word formed in this way. Also known as inverse derivation- retrogressive formation. See also clipping.
BACK-FORMATION: “Back-formation refers to the creation of a word, due to the assumption that it is the derivative of another word, like the creation of enthuse from enthusiasm.”