Exuberant cry (5)
(Other definitions for yahoo that I've seen before include "Human-looking beast in Gulliver's Travels: search engine conglomerate" , "Brutish person created by Dean Swift" , "Rude or coarse person" , "One of Dean Swift's brute people" , "A Swiftian lout" .)
'exuberant cry' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for wahoo that I've seen before include "Ornamental shrub" , "swimmer" , "Large fish related to the mackerel" , "Burning bush" , "in America, yeah baby!" .)