The crossword solution for the term 'Comedian Bill, informally' is COS. This is an abbreviation of the name of Bill Cosby, an American stand-up comedian, actor, musician, author, and convicted sex offender. Cosby began his career as a stand-up comic at the hungry i in San Francisco during the 1960s. He then starred in the television sitcom The Cosby Show, which aired from 1984 to 1992 and was rated as the number one show in America for five years. He has since been involved in numerous other projects, including films, books, and comedy albums.