Back formations

Back formations 
      are words (usually verbs) formed by removing from a noun
 what is thought to be a suffix, and adding a verb ending. In the
following, the right-hand column shows the word from which the back formation is derived.

     emote                          emotion        

     enthuse                       enthusiasm  

      liaise                           liaison          

      sculpt                         sculptor       

     televise                        television     

     The verb legitimize is formed by back formation from the adjective legitimate.