Sullivan (crater on Mercury) definition

(1) English composer of operettas who collaborated with the librettist William Gilbert (1842-1900)

(2) United States educator who was the teacher and lifelong companion of Helen Keller (1866-1936)

(3) United States host on a well known television variety show (1902-1974)

(4) United States psychiatrist (1892-1949)

(5) United States architect known for his steel framed skyscrapers and for coining the phrase `form follows function' (1856-1924)