When not in the first flush, after lunchtime is wisest (4,4,4)
I believe the answer is:
past ones best
'wisest' is the definition.
Both the definition and answer are superlative adjectives.
Maybe they are linked in a way I don't understand?
'when not in the first flush after lunchtime' is the wordplay.
I cannot quite understand how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
'first' could be 'best' (similar in meaning) and 'best' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'is' acts as a link.
Can you help me to learn more?
(Another definition for past ones best that I've seen is " No longer as strong as one was".)