What is "hi-de-hi"

call-and-response exclamation in singing, by 1933, associated with U.S. bandleader Cabell "Cab" Calloway (1907-1994) and especially his signature song "Minnie the Moocher," which dates from 1931.\n\nCalloway recalled in his autobiography that the song came first and the chorus was later improvised when he forgot the lyrics during a radio broadcast.

["Harlem Renaissance Lives," Oxford, 2009]