the analogical creation of one word from another word that appears to be a derived or inflected form of the first by dropping the apparent affix or by modification.
a word so formed, as typewrite from typewriter.
Origin of back formation
First recorded in 1885–90
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for back-formation
the invention of a new word on the assumption that a familiar word is derived from it. The verbs edit and burgle were so created from editor and burglar
a word formed by this process
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012