The term 'SITCOM PIONEER' can be solved by the crossword solution 'LUCY', which is a reference to the iconic American television sitcom 'I Love Lucy'. The show, which aired from 1951 to 1957, starred Lucille Ball and Desi Arnaz and was one of the first sitcoms to become a major hit. It was revolutionary for its time, introducing a variety of innovative techniques that would become staples of the genre.