Reportedly something through which little dog jumps, experiencing such fun? (4-1-4)
I believe the answer is:
cock-a-hoop
'fun?' is the definition.
Both the answer and definition are adjectives. Perhaps they are linked in a way I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for cock-a-hoop that I've seen before include "In high spirits" , "Elated" , "Jubilant" , "Feeling triumphant like male bird with toy" , "Thrilled to bits" .)