Back-formation

/bˈakfɔːmˈeɪʃən/

/bˈækfɔːɹmˈeɪʃən/

Back-formation

a word-formation process in which a new word is created by removing what is mistakenly perceived as a derivative affix from an existing word, often resulting in a shorter word with a different part of speech

Examples

1. Historians agree that Romulus was almost certainly a completely legendary figure, whose name was likely a back-formation from the name Rome, not vice versa.