Fairground attraction (4-2)
(Other definitions for hoop-la that I've seen before include "Throwing fairground game" , "Game in which rings are thrown over objects in order to win them" .)
(Other definitions for ferris wheel that I've seen before include "Fairground ride" , "Attraction at fair" , "Funfair feature and London Millennium attraction" , "London Eye, for example" .)
'fairground attraction' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for merry-go-round that I've seen before include "Fairground attraction" , "Language widely spoken in India" , "Whirligig" , "Fairground ride" , "Carousel" .)