"the 130th Psalm" (one of the seven penitential psalms), so called for its opening words in Latin, literally "out of the depths (have I cried)." From ablative plural of profundum (see profound).
"sudden, unforeseen occurrence," 1779, from French coup de foudre, literally "stroke of lightning," also "love at first sight" (see coup).
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.
Calloway 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]