Like an idiot in cheerful group? (10)
I believe the answer is:
blithering
'like an idiot in' is the definition.
I can't judge whether this definition defines the answer.
'cheerful group?' is the wordplay.
'cheerful' becomes 'blithe' (similar in meaning).
'group?' becomes 'ring' (a ring is a criminal organisation).
'blithe'+'ring'='BLITHERING'
Can you help me to learn more?
(Other definitions for blithering that I've seen before include "talking foolishly" , "Foolish" , "Stupid" , "Contemptible" .)