DCHP-1 Online
whoop-up from the verbal phrase whoop (it) up, enjoy oneself in a boisterous way Esp. West 
n. a noisy party or other celebration.
- 1913 As soon as the general "whoop-up" began, all the traders . . . packed up their outfits snugly and retired. . . .
- 1953 "Ain't you going to have no dance, no rodeo, whoop-up?"
- 1964 Welcome . . . to all . . . who've [made] it to our annual whoop-up.
- 1913 As soon as the general "whoop-up" began, all the traders . . . packed up their outfits snugly and retired. . . .