Yearn to have a fling well back (4,3)
I believe the answer is:
long ago
'well back' is the definition.
Both the definition and answer are adverbs. Maybe there's a link between them I don't understand?
'yearn to have a fling' is the wordplay.
'yearn' becomes 'long-' (synonyms).
'to have' means one lot of letters go next to another.
'fling' becomes 'go' (synonyms).
'long'+'a'+'go'='LONG-AGO'
Can you help me to learn more?
(Other definitions for long ago that I've seen before include "Ages back" , "Many years past" , "In the far past" , "Remote in time" , "Ancient" .)