Season of mellow fruitfulness? (1,4,3,3)
I believe the answer is:
a ripe old age
'fruitfulness?' is the definition.
Both the answer and definition are singular nouns.
Maybe they are linked in a way I don't understand?
'season of mellow' is the wordplay.
I cannot really see how this works, but
'season' could be 'age' (season can mean a period or age) and 'age' is present in the answer.
'of' could be 'o' and 'o' is present in the answer.
'mellow' could be 'ripe' (similar in meaning) and 'ripe' is present in the answer.
The remaining letters 'ald' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?