Back-formation refers to either the process of creating a new lexeme (less precisely, a new "word") by removing actual or supposed affixes, or to the neologism formed by such a process. Back-formations are shortened words created from longer words, thus back-formations may be viewed as a sub-type of clipping.
Each back-formation in this list is followed by the original word from which it was back-formed.
ablute from ablution
aborigine as a mistaken singular for aborigines (correct Latin singular is aboriginal)