Definitions of Sullivan:
- noun: English composer of operettas who collaborated with the librettist William Gilbert (1842-1900)
- noun: United States educator who was the teacher and lifelong companion of Helen Keller (1866-1936)
- noun: United States host on a well known television variety show (1902-1974)
- noun: United States psychiatrist (1892-1949)
- noun: United States architect known for his steel framed skyscrapers and for coining the phrase `form follows function' (1856-1924)
- name: A surname (common: 1 in 1234 families; popularity rank in the U.S.: #105)