"Whoopee!" (3)

(Other definitions for yahoo that I've seen before include "Swift chap" , "service provider" , "Rude, brutish type" , "One of Dean Swift's brutish people" , "Rude or brutish person" .)

(Other definitions for wahoo that I've seen before include "swimmer" , "Large fish related to the mackerel" , "Burning bush" , "Ornamental shrub" , "in America, yeah baby!" .)