Carnival with boos and cheers (6)
I believe the answer is:
fiesta
'carnival' is the definition.
(I've seen this before)
'boos and cheers' is the wordplay.
'boos' becomes 'fies' (I can't justify this - if you can you should believe this answer much more).
'and' is a charade indicator (letters next to each other).
'cheers' becomes 'ta' (both can mean thank you).
'fies'+'ta'='FIESTA'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for fiesta that I've seen before include "Religious event" , "Public celebration in Spain" , "Religious festival in Spain" , "Public whoopee in Spain" , "(Spanish) religious festival" .)